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  • Coleoptera  (217)
  • evolution  (202)
  • Rat
  • temperature
  • Springer  (621)
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  • 1990-1994  (621)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 32 (1993), S. 71-73 
    ISSN: 1436-6215
    Keywords: Rat ; glutamate-induced obesity ; postprandial thermogenesis ; Ratte ; Glutamat-induzierte Adipositas ; postprandiale Thermogenese
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Bei 4 Monate alten Ratten mit Glutamat-induzierter Adipositas wurde die postprandiale Thermogenese über 8 h nach Fütterung von 300, 450 und 600 kJ/kg0,75 einer Pellet-Diät mittels indirekter Kalorimetrie in computergesteuerten Stoffwechselkäfigen mit offenem Kreislauf bestimmt. Bei den adipösen Tieren war die postprandiale Thermogenese nach Aufnahme von 600 kJ/kg0,75 (oberhalb des Energieerhaltungsbedarfs) signifikant auf 40% der Thermogenese der Kontrolltiere reduziert (12,0 gegenüber 31,5 kJ/kg0,75×8 h). Es wird geschlußfolgert, daß die Ratte mit Glutamat-induzierter Adipositas als ein Tiermodell mit beeinträchtigter fakultativer Thermogenese anzusehen ist, die hauptsächlich durch eine Verminderung der sympathischen adrenergen Aktivität verursacht ist.
    Notes: Summary Postprandial thermogenesis was estimated in 4-month-old male rats with glutamate induced obesity after being fed with 300, 450 and 600 kJ/kg0.75 of a pellet diet, respectively by indirect calorimetry in computer-controlled open circuit metabolic cages over 8 h. After an intake of 600 kJ/kg0.75 (above the maintenance energy requirement) postprandial thermogenesis was significantly reduced in the obese animals to about 40% of control rats (12.0 versus 31.5 kJ/kg0.75×8 h). It is concluded that the glutamate obese rat can be accepted as an animal model with impaired facultative thermogenesis, mainly caused by a reduction of sympathetic adrenergic activity.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 9-16 
    ISSN: 1570-7458
    Keywords: Aphid ; alder ; food quality ; temperature ; ovariole number ; Pterocallis alni
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé P. alni DeGeer (Homopt. Callaphididae) vit sur Alnus glutinosa Gaertner pendant toute l'année. L'aulne étant un arbre fixant l'azote, cette étude a été entreprise pour examiner la croissance et la reproduction de ce puceron sur cet arbre afin d'expliquer les changements de la dynamique de sa population. 6 générations successives estivales ont été élevées dans la nature et en température constante au laboratoire. La qualité de l'aliment a été mesurée chaque semaine par une microkjeldahl analyse des concentrations foliaires en azote soluble. La qualité de l'aliment varie saisonnière, mais ne diminue que de 23%; elle semble n'avoir que peu d'effets sur le puceron, puisque la fécondité dans la nature n'est réduite que pendant une génération. Quand la température est maintenue constante, il n'y a pas de différences entre les performances des différentes générations de pucerons. Ainsi, les changements saisonniers dans la croissance et la reproduction des pucerons sont provoqués par la température et non par la qualité de l'aliment.
    Notes: Abstract Six successive summer generations of the alder aphid (Pterocallis alni (DeGeer) (Homoptera: Callaphididae)) were reared simultaneously in the field and under controlled temperature conditions in the laboratory. The growth and reproduction of each generation were recorded. The available food quality for the aphids was measured by weekly analysis of foliar soluble nitrogen concentrations. Although there was a significant change in leaf soluble nitrogen during the season, the decline was only 23% and this did not appear to have an adverse effect on the performance of this aphid. Instead, the major environmental factor affecting the aphid is temperature. This is evidenced by the facts that when aphids were reared at constant temperatures, there were no differences in generation performance, even though food quality varied seasonally. In addition, all generations of the aphid posess the same number of ovarioles, indicating that there is no pre-programmed anticipation of a seasonal deterioration in food quality in this aphid species.
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  • 3
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    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 143-150 
    ISSN: 1570-7458
    Keywords: Bruchidae ; Callosobruchus maculatus ; competition ; development ; evolution ; fecundity ; growth rates ; host preferences ; life tables ; mortality ; natural selection ; net reproductive rate ; oviposition traits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le taux partiel de reproduction nette (R inf0 sup* ) dépend de l'espèce de la plante sur laquelle les œufs sont pondus et du nombre de larves entrant dans la graine. La survie larvaire est réduite par 1/(le nombre de larves par graine) parce qu'une seule larve se développe dans une graine. La fécondité n'est pas modifiée par la compétition subie par les larves, la mortalité larvaire a l'effet le plus important sur R inf0 sup* . Les femelles éliminent ou réduisent la compétition larvaire en dispersant leurs œufs uniformément et font si peu d'erreurs avec une hyperdispersion que l'évolution d'un comportement plus précis n'accroîtrait R inf0 sup* que de 4% au maximum. Des femelles retournant à une distribution des œufs au hasard provoqueraient une réduction de R inf0 sup* de 25% au moins. Les légumineuses généralement cultivées dans l'Inde du Sud sont des hôtes acceptables quand elles sont présentées seules. Le choix des femelles entre 2 hôtes élève R inf0 sup* de 30% ou plus par rapport à une distribution au hasard. Les préférences les plus nettes concernent des combinaisons présentant la plus grande différence de R inf0 sup* . Les femelles qui hyperdispersent leurs œufs, choisissent leurs hôtes et évitent les pertes par compétition en empêchant que les œufs ne donnent plus de descendants que ne le ferait une ponte au hasard. Les particularités de la ponte sont variables et héritables. Les lignées se sélectionnent bien, en fonction de la dispersion de leurs œufs sur les graines, de la discrimination des plantes hôtes, et de la modulation de leur taux de ponte. La sélection naturelle maintient ces particularités du comportement d'une façon sédentaire.
    Notes: Abstract The deposition of eggs by this strain of Callosobruchus maculatus (Fab.) (Bruchidae: Coleoptera) departs from randomness in three ways; eggs are uniformly dispersed, oviposition rates drop when beans begin to carry 2 or more eggs, and there are sharp host preferences. Using random egg placement for the unspecialized condition, these traits are evaluated for their effect on a female's contributions of offspring to the next generation (R0, the net reproductive rate). The major increases in R0 result from females dispersing eggs so uniformly that larval competition is either reduced or eliminated. Females reduce their oviposition rate when the larva from an egg added to a bean is almost certain to die in competitive encounters. Host preferences and larval survival in a host are positively associated with the abundance of the host in South India. The three oviposition traits act together to give and R0 that is 25–50% than that of eggs placed at random. These traits are known to be variable and heritable, hence, the conditions necessary for natural selection are statisfied.
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  • 4
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    Entomologia experimentalis et applicata 71 (1994), S. 201-209 
    ISSN: 1570-7458
    Keywords: Hypothenemus hampei ; coffee berry borer ; abiotic mortality ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mortality of the coffee berry borer was studied under controlled laboratory conditions in Tapachula, Mexico. For adult female borers subjected to a range of relative humidities (RH) without food at 25°C, the longest mean survival time (20 days) was obtained at 93.5% RH. Adult borer survival was also studied at a range of temperatures for a fixed relative humidity (93.5% RH); at 20°C mean survival time was 28 days. Fecundity and mortality of borer stages in berries was studied for a range of humidities at 25°C. Maximum fecundity was obtained at 90 and 93.5% RH. Immature stages were ejected from the berry at 84% RH and above, which is interpreted as a form of brood hygiene.
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  • 5
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    Springer
    Entomologia experimentalis et applicata 72 (1994), S. 255-263 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; behavior ; thermal biology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In short-term field trials at combinations of ambient temperature (°C) and insolation (W·m−2), larval Colorado potato beetles (Leptinotarsa decemlineata [Say] [Coleoptera: Chrysomelidae]) were observed after their release on the adaxial surface of leaflets on potato plants (Solanum tuberosum L. Solanaceae). The larvae either began feeding or moved under the leaflet; mean interval from release to expression of these behaviors (2.9±0.05 min [n =358]) was independent of air temperature and insolation. Proportion of larvae moving under the leaflet increased logistically with both air temperature and insolation. A 1 W·m−2 change in insolation (P) evoked the same effect on this proportion as a 0.0838 °C change in air temperature (T a ), so the two quantities were combined as T*=T a +P·0.0838 °C/(W·m−2), which has units of °C. The proportion of larvae moving under the leaflet increased logistically with T*. In 1-day field trials we monitored air temperature, insolation and proportion of larvae under the leaflet, and compared the latter to predictions from the logistic regression derived from the short-term trials. Consistently more larvae occurred under leaflets than predicted from the logistic regression; this bias diminished as T* increased until at T*≥40 °C, observed and predicted proportions were equal. This pattern of deviation from the predictions of the logistic regression is consistent with a thermoregulatory strategy in which larvae move away from hostile conditions, rather than seek optimal conditions.
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  • 6
    Electronic Resource
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    Entomologia experimentalis et applicata 72 (1994), S. 273-279 
    ISSN: 1570-7458
    Keywords: oviposition ; stimulation ; narcosis ; carbon dioxide ; age ; temperature ; photoperiod ; Bombus terrestris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four experiments aimed at the stimulation of starting oviposition were carried out with bumblebee queens (Bombus terrestris L.) from colonies belonging to the ecotype of Central Western France and reared in a glasshouse. After mating, queens were narcotized with carbon dioxide, confined singly in small boxes (11×5×4.5 cm) and kept in a dark room at 28–29 °C and 60%–65% r.h. They were fed on a sugar solution and a pollen-syrup mixture. No effects were discernible if the narcosis was applied 20 to 30 days after mating instead of 5 days, nor if the queens were submitted to a 4 to 5 day period at 34°C following narcosis. Survival rates ranged from 65% to 68 %. If the queens were reared under fluorescent tubes (L8∶D16) after narcosis the mean delays to egg-laying were significantly reduced compared to a dark treatment (21 days instead of 39), as was their variability (s.e.=1.6 day instead of 3.1 days). The survival rates were respectively 73% and 67%. Under the same photoperiod (L8∶D16) the CO2 narcosis repeated at a 24h interval had the same efficacy whether its duration was 10 min or 5 min. The delays to egg-laying were respectively 20 days (s.e=1.5) and 25 days (s.e.=4.8) with survival rates close to 73%. Egg-laying could also be induced in non-narcotized queens with a survival rate of 54% and delays to oviposition close to those of queens narcotized 2×10 min.
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  • 7
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    Entomologia experimentalis et applicata 73 (1994), S. 221-229 
    ISSN: 1570-7458
    Keywords: Agaonidae ; host choice ; dispersal ; Ficus ; migration ; Moraceae ; take off ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ficus burtt-davyi, like most other fig species (Ficus, Moraceae), is exclusively pollinated by its own unique species of fig wasp, in this caseElisabethiella baijnathi (Chalcidoidea, Agaonidae). Because fig crop development on any one tree is usually synchronised, the small and short-lived female wasps have to migrate and find other trees bearing figs which are at suitable stage of development for oviposition. However, the likelihood of successful location and subsequent arrival at a new host tree is dependent on distance and the effect of environmental factors such as wind and temperature. This study examines the relationship between ambient temperatures and the timing of fig wasps emergence from their natal figs and the commencement of their dispersal flight. The behaviour of the wasps arriving at figs which were ready to be pollinated was also examined. The female wasps did not appear to distinguish between the figs and other parts of the tree when in flight. However, after landing on the tree their search for figs was more directed as they visited more figs than leaves. Short-range recognition of figs appears to be by contact chemo-reception, but the wasps showed a preference for entering figs which did not already contain a female wasp.
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  • 8
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    Entomologia experimentalis et applicata 69 (1993), S. 13-20 
    ISSN: 1570-7458
    Keywords: Artificial diets ; Coccinellidae ; rearing ; biological control ; Chilocorus spp. ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Promising diets were screened and the most successful modified with additives used in artificial diets for other entomophagous insects. Two suitable diets were obtained, one for adults and one for larvae ofChilocorus nigritus (Fabricius) (Coleoptera: Coccinellidae). They were still inferior to natural prey and not adequate as the sole food source for rearing consecutive generations. They are valuable as substitute food in the insectary during shortages of natural prey. Oleander scaleAspidiotus nerii Bouché andAsterolecanium miliaris (Boisduval) were evaluated as natural prey forC. nigritus and two other potential biocontrol agents in southern Africa,C. bipustulatus (Linnaeus) andC. infernalis Mulsant.A. nerii andA. miliaris were suitable for all life stages ofC. nigritus and adults ofC. bipustulatus andC. infernalis. A. miliaris was inadequate for larvae ofC. bipustulatus andC. infernalis.
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  • 9
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    Entomologia experimentalis et applicata 71 (1994), S. 177-180 
    ISSN: 1570-7458
    Keywords: aflatoxin ; Carophilus ; Zea mays ; corn ; plant resistance ; Coleoptera ; Nitidulidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 10
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    Entomologia experimentalis et applicata 72 (1994), S. 25-31 
    ISSN: 1570-7458
    Keywords: diapause induction ; photoperiod ; temperature ; Phyllonorycter blancardella ; spotted tentiform leafminer ; Lepidoptera ; Gracillariidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The role of photoperiod and temperature in the induction of overwintering diapause inPhyllonorycter blancardella (F.) (Lepidoptera: Gracillariidae) was examined in the laboratory and field using leafminers from commercial apple orchards in Ontario, Canada.P. blancardella exhibited a long-day response to photoperiod: long daylengths resulted in uninterrupted development whereas short daylengths induced diapause. The estimated critical photoperiod for diapause induction was L14.25∶D9.75. The larvae of leafminers destined to enter diapause took ca. 3× longer to complete development than the larvae of non-diapausing leafminers. The development prolonging effect of photoperiod decreased with decreasing daylength. Temperature modified the diapause inducing effect of photoperiod. At L14.25∶D9.75, diapause incidence was similar at 15 and 20°C but was lower at 25°C. Photoperiod also altered the normal relationship between development rate and temperature. At L14.25∶D9.75, the duration of larval development of diapausing leafminers was similar at 15, 20 and 25°C. Temperature alone is unlikely to have a role in the induction of diapause because leafminers exposed to natural late summer and fall temperature regimes and L16∶D8 did not enter diapause.
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  • 11
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    Entomologia experimentalis et applicata 72 (1994), S. 125-133 
    ISSN: 1570-7458
    Keywords: growth rate ; consumption rate ; molt ; nutritional ecology ; rutin ; temperature ; thermocycles ; tobacco hornworm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of different concentrations of rutin and constant temperature (20 °C) versus alternating temperatures (23∶15 °C) on growth, molting and food utilization efficiencies of third instar tobacco hornworms (Manduca sexta) were determined. Relative consumption rate (RCR) and relative growth rate (RGR) were significantly higher for larvae at the alternating thermal regime compared to those at the constant (representing the average) temperature. With increasing concentrations of rutin, the negative effect of rutin on RCR and RGR increased for the larvae in the alternating thermal regime; however, at the constant temperature, rutin had little effect. The alternating thermal regime promoted synchrony in the timing of spiracle apolysis (the earliest morphological marker of molt). Rutin disrupted that synchrony. I discuss how patterns of host plant resistance may be altered with a decrease, in amplitude of diurnal temperatures (as has been documented recently for temperate regions) through the uncoupling of herbivore performance and allelochemical concentration. I conclude that simultaneous consideration of fluctuating temperatures and allelochemicals is advisable when assessing the effects of temperature and allelochemicals on performance of insect herbivores because interactive effects between temperature and dietary components occur and perhaps are common.
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  • 12
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    Entomologia experimentalis et applicata 73 (1994), S. 127-137 
    ISSN: 1570-7458
    Keywords: Heteroptera ; Anthocoridae ; Orius insidiosus ; Orius tristicolor ; Orius majusculus ; Orius albidipennis ; diapause induction ; termination ; photoperiod ; temperature ; sensitive stages ; biological control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Photoperiodic induction of reproductive diapause at 18°C was investigated in fourOrius [Heteroptera: Anthocoridae] species.Orius insidiosus (Say) displayed a long-day response with a critical photoperiod between L11:D13 and L12:D12. Diapause in this species was terminated rapidly when the temperature and/or the daylength were increased.Orius majusculus (Reuter) also displayed a long-day response. The critical photoperiod fell between L14:D10 and L16:D8. Diapause in this species was not terminated within 14 days when both temperature and daylength were increased. InOrius albidipennis (Reuter) no diapause could be induced at photoperiods varying from L8:D16 to L16:D8. InOrius tristicolor (White) a high proportion of diapause was found at all photoperiods tested. The effect of temperature on photoperiodic induction of diapause was studied inO. insidiosus at L10:D14. Diapause occurred at 18°C, 21°C and 25°C, but not at 30°C. Again, diapause was terminated rapidly after transfer to 25°C/L16:D8. Exposing only the nymphal instars 1–5 to short daylength was not enough to induce diapause in the whole population ofO. majusculus. Orius predatory bugs are used as biocontrol agents against western flower thrips,Frankliniella occidentalis (Pergande) [Thysanoptera: Thripidael, in greenhouses. The consequences of photoperiodic induction of diapause for the success of early season releases ofOrius are discussed.
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  • 13
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    Entomologia experimentalis et applicata 63 (1992), S. 115-121 
    ISSN: 1570-7458
    Keywords: Pea weevil ; Bruchus pisorum ; Bruchidae ; Coleoptera ; flower feeding ; nectar robbing ; pea ; Pisum sativum ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pea flower feeding by adult pea weevils, Bruchus pisorum (L.) (Coleoptera: Bruchidae), with special emphasis on nectar feeding, was investigated in a series of laboratory experiments. Male and female adults robbed nectar from flowers of the garden and field pea, Pisum sativum L., and females which fed on the nectar, petals, and female organs of pea flowers lived significantly longer than those denied food and water and those that fed on water only. The results of other experiments suggested that pea flower qualities other than pollen influenced the reproductive success of female B. pisorum. It is hypothesized that pollen seeking B. pisorum effected cross-pollination in the wild progenitor of the modern-day autogamous pea, and adult pea weevils of both sexes rob pea nectar to obtain a readily available source of energy to sustain flight.
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  • 14
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    Entomologia experimentalis et applicata 64 (1992), S. 31-36 
    ISSN: 1570-7458
    Keywords: Eurydema rugosa ; adult diapause ; diet ; photoperiod ; temperature ; postdiapause development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract InEurydema rugosa Motschulsky (Heteroptera: Pentatomidae), the type of food supplied (i.e. seeds or leaves of the brown mustard,Brassica juncea Hemsel) and photoperiod, which control the induction of adult diapause, do not play a role in the initiation of reproduction after overwintering. A temperature above 13.2°C was required to start reproduction. After its initiation, however, short-day conditions on seeds induced diapause again in some adults. Although a diet of seeds under long-day conditions, in common with short-day conditions, induced diapause in young adults (Numata & Yamamoto, 1990), it did not reinduce diapause in adults after overwintering. Thus,E. rugosa that had overwintered became sensitive to diapause-inducing photoperiod again but not to dietary factors.
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  • 15
    ISSN: 1570-7458
    Keywords: Ceutorhynchus inaffectatus ; Coleoptera ; Curculionidae ; Hesperis matronalis ; Dame's violet ; Brassicaceae ; Cruciferae ; glucosinolates ; feeding stimulants ; host plant specificity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ceutorhynchus inaffectatus Gyllenhal (Coleoptera: Curculionidae:Ceutorhynchinae) is a monophagous species feeding only onHesperis matronalis L. (Cruciferae) in North-western Europe. Feeding responses of this weevil to five glucosinolates from its host plant were compared with the responses to four glucosinolates from non-host plants. The major glucosinolates in the host plant were isolated and identified: 6-methylsulphinylhexylglucosinolate (glucohesperalin), 3,4-dihydroxybenzylglucosinolate (glucomatronalin), 3-O-apiosylglucomatronalin, a 3,4-dihydroxybenzoylester and a 3,4-dimethoxybenzoylester of 3-O-apiosylglucomatronalin. The three glucosinolates containing apiose were powerful feeding stimulants forC. inaffectatus while the other host plant compounds and allyglucosinolate (sinigrin), 3-methylsulphinylpropylglucosinolate (glucoiberin), benzylglucosinolate (glucotropaeolin) and p-hydroxybenzylglucosinolate (sinalbin) were weaker stimulants. The role of glucosinolates in host plant selection ofC. inaffectatus and related monophagous crucifer feeders is discussed.
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  • 16
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    Entomologia experimentalis et applicata 68 (1993), S. 127-142 
    ISSN: 1570-7458
    Keywords: tobacco hornworm ; Manduca sexta ; nutritional ecology ; rutin ; temperature ; dietary self-selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The possibility of avoidance of and dietary self-selection relative to the flavonol rutin was examined for third instarManduca sexta for two thermal regimes and for larvae previously reared on plain or rutin diet. Temperature affected all of the performance indices examined, except efficiency of conversion of digested food. Significant interactive effects between temperature and diet occurred for relative consumption rate, relative growth rate and the food utilization efficiencies. For example, at the warm daytime temperature, relative growth rate prior to head capsule slippage was lower for caterpillars previously reared on rutin diet compared to those reared on plain diet. In contrast, at the cool daytime temperature, the relative growth rates were similar for caterpillars reared on plain diet and on 6 μmoles rutin diet. Consequently, in some treatments (5 of 12), caterpillars with a history of rutin in their diet had lower relative growth rates than those experiencing rutin for the first time. Despite rutin's impact on food utilization indices and negative effect on relative growth rate, the caterpillars did not avoid rutin nor was there evidence of regulation of the intake of rutin. The lack of metabolic feedback is discussed.
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  • 17
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    Entomologia experimentalis et applicata 70 (1994), S. 217-225 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; plant resistance ; glandular trichomes ; host preference ; behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Choice and no-choice studies were conducted to determine how the glandular trichomes of the wild potato,Solanum berthaultii Hawkes, affect host preference of the Colorado potato beetle,Leptinotarsa decemlineata (Say). Given a feeding choice betweenS. tuberosum andS. berthaultii, larvae and adults preferred the foliage ofS. tuberosum, but adults were more discriminating. When foliage ofS. berthaultii was appressed toS. tuberosum leaflets, fewer adults fed on the appressed leaflets. When given a choice between ‘trichome-intact’ and ‘trichome-removed’S. berthaultii foliage, adults preferred to feed on the latter. The preference for ‘trichome-removed’ foliage and the percent of adults initiating feeding, increased with the degree of trichome removal. These studies provide evidence that the resistance ofS. berthaultii is associated with feeding deterrents localized in the glandular trichomes, thatS. berthaultii possesses more than one mechanism of resistance to the Colorado potato beetle, and that the expression of resistance is dependent on the developmental stage of the insect.
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  • 18
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    Entomologia experimentalis et applicata 60 (1991), S. 173-182 
    ISSN: 1570-7458
    Keywords: Genetics ; evolution ; host adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When populations are exposed to different environments, evolutionary processes can lead either to genetically differentiated strains or to the appearance of increased generalism at the individual level. For evolution to occur, genetic variability in performance in different environments is required. Here, intraspecific genetic variation across environments was estimated in the flour beetle Tribolium castaneum (Herbst) by comparing the responses of two strains of T. castaneum to different flour types. Replicated groups from each strain were allowed to develop on either the standard whole wheat medium or on one of four novel flours (wheat, rice, corn and oat). In several of the novel flours, clear differences in mean development time or population size of one or both strains were seen relative to performance in the standard medium. Moreover, the strains differed significantly in their phenotypic responses to the flours. One strain did particularly poorly on oat flour. Reduced oviposition, reduced larval survivorship and increased larval cannibalism were examined as possible causes of the low productivity on oat flour. These three factors accounted for about 70% of the reduction in population size when this strain oviposited and developed in oat flour. The difference between these two outbred strains in response to these five flours suggests that genetic variation in resource use is present within T. castaneum and may also be present within strains and natural populations in grain storage facilities. Such variation would permit an evolutionary response to selection in multiple environments (flours). This process has agricultural implications when several types of grain are stored in a single location because it could eventually lead to the evolution of highly generalized populations of T. castaneum, an important pest of stored products.
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    Entomologia experimentalis et applicata 58 (1991), S. 289-293 
    ISSN: 1570-7458
    Keywords: Spider mites ; Tetranchus urticae ; damage ; feeding ; temperature ; photoperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Wir untersuchten den Einfluss von Temperatur und Licht auf die Saugtätigkeit von Tetranychus urticae auf Bohnenpflanzen und fanden eine nicht-lineare Beziehung zwischen Temperatur und Saugaktivität. Die Saugintensität stieg bei Temperaturen über 10 °C an bis zum Saugmaximum bei 35 °C und sank dann relativ rasch ab. Permanentes Licht- oder Dunkelregime übte keinen Einfluss auf die Saugleistung aus. Aufgrund der beobachteten Zusammenhänge zwischen Temperatur, Saugintensität und Intensität der Ausbildung der Schadsymptome entwickelten wir ein verbessertes Mass (‘mite-load’) für die Erfassung des Spinnmilbenstresses auf die Wirtspflanze. Die präsentierten Daten zeigen, dass mit der ‘mite-load’ Funktion die Saugschäden von T. urticae präziser erfasst werden können als mit den bisher gebräuchlichen Milbendichten pro Blatt oder Milbentagen.
    Notes: Abstract The influence of temperature and light regime on the feeding intensity of Tetranychus urticae (Koch) (Acari: Tetranychidae) was studied on bean plants. A nonlinear relationship was found between temperature and feeding activity of T. urticae. The feeding intensity increased from 10 °C to 35 °C. At 10 °C there was practically no feeding, whereas at 35 °C maximum feeding occurred. above 35 °C the activity of the mites decreased. No difference could be found in the feeding intensity of mites kept at permanent darkness or permanent light. Based on the observed relationship between temperature and feeding activity and intensity of damage symptoms, respectively, we propose the use of a mite-load function to define the mite stress imposed on the plant.
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  • 20
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    Entomologia experimentalis et applicata 63 (1992), S. 81-86 
    ISSN: 1570-7458
    Keywords: Laboratory bioassay ; olfactometer ; olive bark beetle ; Phloeotribus scarabaeoides ; Coleoptera ; Scolytidae
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    Topics: Biology
    Notes: Abstract Bioassay conditions with a glass olfactometer for the olive bark beetle, Phloeotribus scarabaeoides Bern. (Coleoptera: Scolytidae), have been investigated. The best temperatures and light intensities were between 17 and 28° C and 1000 and 1500 lux, respectively. The best response was obtained with newly emerged individuals from reproduction galleries with no feeding period.
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  • 21
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    Entomologia experimentalis et applicata 65 (1992), S. 129-140 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Bembidion lampros ; Pterostichus cupreus ; P. melanarius ; diet ; egg production ; egg size variation ; pirimicarb ; fat reserves
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    Topics: Biology
    Notes: Abstract Egg size was measured at different rates of egg laying in three polyphagous carabid species, known to be useful predators of cereal aphids; the small Bembidion lampros Herbst and the medium-sized Pterostichus cupreus L. and P. melanarius Illiger. Variations in fecundity, as well as the ability of the medium-sized species to also build up fat reserves, were obtained when beetles were subjected to different dietary regimes consisting of aphids, or foods with a lower or higher protein content. Egg size was found to be dependent on the rate of egg laying within a species. A diet of cereal aphids appeared to be adequate for egg production in these polyphagous carabids, but female P. cupreus were unable to build up fat reserves when they ingested aphids contaminated with the aphicide pirimicarb. Beetles were able to devote resources to more and larger eggs (B. lampros), or to larger eggs and/or fat reserves (P. melanarius/P. cupreus) when given access to a carbohydrate-rich food with low protein content. The highest rate of egg laying was obtained when female P. cupreus and P. melanarius were given a more varied diet at frequent intervals; including regular shifts between unsprayed aphids, carbohydrate-rich food and protein-rich maggots. Within the varied diet treatment a negative relationship was obtained between egg size and egg number among similar-sized individuals of P. cupreus and P. melanarius; females producing the largest number also laid the smallest eggs. Egg size affected larval survival, since first instars hatching from large eggs were found to survive longer than those hatching from small eggs. The influence of differences in food intake on reproduction, maintenance metabolism, and survival of fieldinhabiting carabids is discussed.
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  • 22
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    Entomologia experimentalis et applicata 65 (1992), S. 205-214 
    ISSN: 1570-7458
    Keywords: Bird cherry-oat aphid ; Rhopalosiphum padi ; alate development ; crowding ; photoperiod ; plant quality ; temperature
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    Notes: Abstract Experiments indicated that for offspring of apterousRhopalosiphum padi (L.) (Hemiptera: Aphididae), photoperiod and crowding were the most important determinants of wing development whereas crowding and plant quality were more significant for the next generation. Plant quality became increasingly important as temperature increased while crowding became less so. More alates developed on plants previously infested with aphids, indicating that aphid feeding reduced plant quality. High temperature suppressed alatoid production, but could be overcome by crowding. Temperature appeared to influence wing development indirectly rather than directly by acting on the aphid through the plant. Adult weight and potential fecundity were also reduced for aphids which fed on previously infested plants.
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  • 23
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    Entomologia experimentalis et applicata 65 (1992), S. 235-240 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Tenebrionidae ; Pterohelaeus darlingensis ; Gonocephalum macleayi ; false wireworms ; sampling
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    Notes: Abstract Counts of adults of the false wirewormsGonocephalum macleayi (Blackburn) andPterohelaeus darlingensis Carter in pitfall traps in burnt, mulched and sorghum treatments conformed to Taylor's power law. Within a species there were no significant differences in distributions of counts of either sex in any habitat butG. macleayi were more aggregated thanP. darlingensis (Taylor'sb 1.35 and 1.26, respectively). Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling are developed for each species using Taylor's parameters for combined data over all habitats.
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  • 24
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    Entomologia experimentalis et applicata 65 (1992), S. 247-257 
    ISSN: 1570-7458
    Keywords: Population genetics ; microgeographic differentiation ; leaf-beetles ; Chrysomelinae ; Coleoptera
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    Notes: Abstract We usedF-statistics to quantify the population structure of two sympatric species of leaf beetles,Oreina cacaliae andO. speciosissima (Chrysomelinae, Coleoptera), which share the same microhabitat since they feed on the same herbaceous host plants. We measured genetic differentiation at six allozyme loci 1) among populations separated by relatively small distances (40 to 250 kilometers), 2) within each population, and 3) between sexes within populations. For both species, the populations studied are not panmictic. For each population, heterozygosities are relatively high, but the observed heterozygosities are generally lower than the expected values. Overall, within-population differentiation is high and similar for both species (F is=0.326 forO. cacaliae and 0.332 forO. speciosissima). Additionally, populations of both species are highly differentiated (F st=0.234 versus 0.051 forO. speciosissima). ForO. cacaliae,F is andF st are greater among females than among males, while forO. speciosissima,F st is sustantially greater among the males whileF is is slightly greater among males. Differences in gene frequency among the sexes were statistically tested using a modifiedF st with sex as the defining category, and the sexes differed significantly with the exception of one population inO. cacaliae. Possible explanations for this difference are discussed.
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  • 25
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    Entomologia experimentalis et applicata 66 (1993), S. 127-134 
    ISSN: 1570-7458
    Keywords: Ooencyrtus nezarae ; parasitoid ; adult diapause ; rate of oviposition ; photoperiod ; temperature
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    Notes: Abstract Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) was reared on eggs ofRiptortus clavatus (Thunberg) (Heteroptera: Alydidae) at various temperatures under long-day (L16:D8) or short-day (L10:D14) conditions. There was no diapause during egg, larval or pupal stages under any set of conditions examined. However, at 15°C under short-day conditions, vitellogenesis was arrested in all adult females and they entered diapause. At 15°C under long-day conditions, or at 20°C under short-day conditions, some adult females entered diapause. Under the latter set of conditions, the adult females laid eggs but they laid fewer eggs than under long-day conditions, Even at 25°C, under short-day conditions, adult females laid fewer eggs than under long-day conditions, and this low rate of oviposition was attributed to the retarded development of ovaries. Diapause adults reared at 15°C were more resistant to low temperature than nondiapause adults reared at 25°C.
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  • 26
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    Entomologia experimentalis et applicata 66 (1993), S. 161-169 
    ISSN: 1570-7458
    Keywords: avoidance behaviour ; capture efficiency ; Coleoptera ; time-lapse video ; visual recording
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    Topics: Biology
    Notes: Abstract Pitfall trap capture forSitophilus oryzae (L.),S. zeamais (Motschulsky),S. granarius (L.),Tribolium confusum (Duval),T. castaneum (Herbst);Oryzaephilus surinamensis (L.),Cryptolestes pusillus (Schonherr),Rhyzopertha dominica (Fabr.), andProstephanus truncatus (Horn) in millet was assessed by visual and time-lapse video recordings. The behaviour of different beetle species in arenas containing millet was monitored over 24 h and the frequency of encounters with the trap rim resulting in capture recorded. The capture efficiency of four types of pitfall traps (i.e. polystyrene, polythene, glass and tin-plated steel can) with rims exposed or submerged below the millet surface level were compared. Capture was related to beetle size, locomotory rate, and beetle behaviour at the trap rim as well as trap design and placement. The lighter and smaller species were least captured. Glass jars were more effective than plastic and metal containers. Traps placed with their rims submerged below the grain surface level were more efficient than those with rims exposed. Capture rate was unrelated to trap size. The frequency of encounters with trap rims was not correlated with capture rate. Three types of avoidance behaviours at the trap rims i.e. probing, skirting and spontaneous retreat, were related to capture rate, spontaneous retreat being the most effective escape mechanism and probing least.
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  • 27
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    Entomologia experimentalis et applicata 65 (1992), S. 39-47 
    ISSN: 1570-7458
    Keywords: Development ; fecundity ; geographical variation ; Coleoptera ; Bruchidae ; ecology ; Phaseolus
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    Notes: Abstract Zabrotes subfasciatus (Boheman) (Coleoptera:Bruchidae) is native to parts of Central and South America but has now been spread to many others areas. It commonly infests the seeds of both Lima beans, Phaseolus lunatus, and common beans, Phaseolus vulgaris. Five geographic populations were found to differ in fecundity, patterns of egg distribution, times of development and adult sizes when they were kept under the same conditions. Each population also differed unpredictably from the others in its response to different cultivars of host seed. These differences have been shown to be of considerable importance in determining the potential pest status of the populations and should also promote caution in making predictions about the responses of different populations to new cultivars of bean for agricultural use.
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    Entomologia experimentalis et applicata 66 (1993), S. 191-196 
    ISSN: 1570-7458
    Keywords: Leptinotarsa decemlineata (Say) ; Coleoptera ; Chrysomelidae ; distribution ; diapause ; overwintering ; mortality
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  • 29
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    Entomologia experimentalis et applicata 70 (1994), S. 27-39 
    ISSN: 1570-7458
    Keywords: almond seed wasp ; Eurytoma amygdali ; diapause termination ; insect dormancy ; temperature ; prolonged diapause ; photoperiod ; Hymenoptera
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    Notes: Abstract Diapausing larvae ofEurytoma amygdali Enderlein (Hymenoptera, Eurytomidae) were collected in early August and late September. They were subjected to various photoperiod and temperature regimens for up to 20 weeks, then kept at L16:D8 and 19°C for another 14 to 26 weeks for diapause to be terminated and pupation to take place. Photoperiod did not affect diapause completion. It was confirmed that the two morphologically distinct diapause stages have different temperature requirements for their completion. The first diapause stage was completed synchronously at temperatures between 16 and 19°C. A higher temperature of 26°C delayed diapause development. The second stage required lower temperatures between 4 and 10°C. Spontaneous termination of dipause was observed at constant 19°C. When applied to the first diapause stage for 20 weeks, low temperatures made the larvae refractory to subsequent intermediate temperatures. The first stage was thus maintained until a higher temperature of 26°C made the larvae regain their ability to respond to the intermediate temperatures and complete this stage. Larvae grown in Retsou almonds had a higher diapause intensity than larvae grown in Truoito almonds. The results suggest that, in nature, the high temperatures of late summer and early autumn are likely to maintain the first diapause stage. Subsequently, the less warm temperatures of autumn allow the completion of the first stage by late autumn, and the low temperatures of late autumn and of winter allow the completion of the second diapause stage by mid winter.
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    Entomologia experimentalis et applicata 70 (1994), S. 201-208 
    ISSN: 1570-7458
    Keywords: Sitophilus oryzae ; S. zeamais ; Coleoptera ; Curculionidae ; flight activity ; symbiosis ; vitamin ; amino acid
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    Topics: Biology
    Description / Table of Contents: Résumé Les performances de vol de nombreuses souches deSitophilus oryzae L. etS. zeamais Mots. (Coleoptera, Curculionidae) ont été comparées sur blé. Il s’avère que les mâles sont plus actifs que les femelles et queS. zeamais possède une meilleure aptitude au vol queS. oryzae. De plus, dans les deux espèces élevées sur blé, seuls les charançons normalement symbiotiques sont capables de voler, tandis que les aposymbiotiques ont perdu ce pouvoir. En complémentant la nourriture avec des vitamines (acide pantothénique et riboflavine) et certains acides aminés (phénylalanine et proline), cette activité a pu être restaurée en partie. L’influence de la symbiose sur l’aptitude au vol du charançon du genreSitophilus est commentée en fonction du métabolisme énergétique (coenzymes, proline) et du rôle joué par la symbiose dans ce comportement qui permet d’augmenter la dissémination de l’espèce.
    Notes: Abstract The flight activity (take-off) of various strains ofSitophilus oryzae L. andS. zeamais Mots. (Coleoptera, Curculionidae) have been compared on wheat. It was shown that males are more active than females and thatS. zeamais, is more active thanS. oryzae. Furthermore, in the two species, when reared on wheat kernels, only symbiotic weevils were able to fly, while aposymbiotic insects did not. By supplementation of the diet with vitamins (pantothenic acid, riboflavin) and amino acids (phenylalanine and proline), this activity could be restored in part. The influence of symbiosis on the flight ability ofSitophilus weevil is discussed in relation to the energy metabolism (coenzymes, proline), the role played by symbiosis in this behaviour and its possible effect on the dissemination of the species.
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  • 31
    ISSN: 1570-7458
    Keywords: Beauveria bassiana ; Leptinotarsa decemlineata ; larval infection ; adult survivor ; fecundity ; egg hatchability ; inoculum dosage ; temperature
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    Description / Table of Contents: Résumé Les effets secondaires de l'hyphomycète entomopathogène, Beauveria bassiana (Bals.) Vuill. sur la fécondité et la fertilité des insectes survivant à l'infection fongique ont été étudiés chez les adultes du doryphore Leptinotarsa decemlineata Say (Coleoptera:Chrysomelidae) issus de larves contaminées en début de 4ème stade. Les insectes maintenus à 22°C ont présenté une réduction de leur potentiel reproductif. Ainsi, suivant la dose d'inoculum fongique, le nombre total d'oeufs pondus par femelle et le nombre moyen d'oeufs par opplaque ont baissé de 20% à 56% et de 18% à 46%, respectivement. En revanche, à 25°C la fécondité des adultes survivants n'a pas été affectée par la maladie. Cette variabilité en fonction des conditions thermiques peut être liée à la diminution de l'effet-dose du champignon sur les larves à 25°C par rapport à 22°C. Par ailleurs, quelles que soient les conditions thermiques (22°C ou 25°C) on ne constate aucun changement significatif de la fertilité des oeufs pondus par les femelles survivantes. Les auteurs concluent que les effets secondaires de B. bassiana sur la fécondité du doryphore dépendent des conditions thermiques et qu'ils pourraient devenir négligeables à des températures élevées en plein champ.
    Notes: Abstract Secondary effects of the entomopathogenic hyphomycete Beauveria bassiana (Bals.) Vuill. were investigated on adults of Leptinotarsa decemlineata Say (Coleoptera:Chrysomelidae) treated as newly moulted 4th-instar larvae. Fecundity and egg hatching were monitored in surviving females mated with surviving males. When reared at 22°C, adult survivors showed a lessening of their reproductive potential during their whole life. According to the fungal inoculum dosage, the reductions of the total number of eggs laid per female and the mean number of eggs per egg mass ranged from 20% to 56% and from 18% to 46%, respectively. In contrast, at 25°C, the fecundity of survivors was not affected by the fungal infection. This variability of the secondary effects of B. bassiana according to temperature conditions might be related to the lower infection level of treated larvae at 25°C. Moreover, at both temperatures, eggs laid by females surviving fungal infection as larvae were as fertile as eggs laid by control insects. It is concluded that secondary effects of B. bassiana on the fecundity of the Colorado Potato Beetle are temperature-dependent and that they could become negligible at high temperatures under field conditions.
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    Entomologia experimentalis et applicata 72 (1994), S. 135-143 
    ISSN: 1570-7458
    Keywords: potassium ; rutin ; temperature ; food utilization efficiencies ; molt ; nutritional ecology ; Manduca sexta
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    Topics: Biology
    Notes: Abstract the simultaneous effects on an insect herbivore (third instar tobacco hornwormManduca sexta (L.): Sphingidae) of temperature (daytime temperatures of 20 °C, 25 °C and 30 °C), a mineral that may play a role in plant defense (potassium) and a common allelochemical (rutin) were examined in a factorial experiment. To manipulate potassium levels, a modified diet with limited plant material was used as the base and KCl and rutin added. Temperature affected efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), time to head-capsule slippage, stadium duration, relative consumption rate (RCR) and relative growth rate (RGR) but not food consumed, biomass gained and approximate digestibility (AD). Potassium concentration influenced all of the variables except AD, time to head-capsule slippage (HCS), duration of the stadium and percent of stadium time to HCS. Rutin impacted negatively on all of the variables except food consumed. Compared to larvae on the non-rutin diets, fewer larvae fed rutin survived through molt initiation to ecdysis and fewer successfully completed ecdysis. Temperature and rutin had interactive effects for AD, ECD, RCR, RGR, time to HCS, and percent of stadium required to reach HCS. Rutin and potassium had interactive effects for biomass gained, RCR, ECI, time to HCS, duration of stadium, and percent of stadium required to reach HCS. Comparison of larval responses on an average potassium concentration (3.1%) versus high concentration (6.1%) showed that at the low daytime temperature increasing potassium concentration depressed biomass gained, but at the warmer temperatures potassium concentration had little effect unless rutin was present. In addition, potassium concentration had little impact on ECI unless rutin was present. These results indicate that significant interactive effects occur among temperature, potassium and rutin, and thus suggest that such interactive effects on larval performance may be common under field conditions, which are characterized by varying temperature and different concentrations of minerals and allelochemicals in hostplants.
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    Entomologia experimentalis et applicata 73 (1994), S. 39-50 
    ISSN: 1570-7458
    Keywords: Leptinotarsa decemlineata ; Coleoptera ; Chrysomelidae ; distribution ; overwintering ; diapause ; cultural control ; trap cropping
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    Notes: Abstract Overwintering Colorado potato beetles (Leptinotarsa decemlineata (Say)) were concentrated primarily within woody borders, and mortality was lower in borders than in potato fields. After overwintering, only 15–44% of live beetles were in the potato fields. In experiments with small plots, colonization of fields from woody borders was reduced ∼60% by a trap crop, either treated with adulticide or with beetles collected daily. Such trap crops, or simply pitfall traps to prevent colonization from woody borders, could significantly reduce early-season adult numbers and subsequent larval populations. However, success is dependent on the local densities of overwintered beetles, and the prevalence of arrestment behavior in the case of trap crops.
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  • 34
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; potato ; plant resistance ; selection ; adaptation
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    Notes: Abstract Thirty cohorts of the Colorado potato beetle (CPB) were reared for ten consecutive generations on the cultivated potato,Solanum tuberosum, and on two accessions (PI 473331 and PI 473334) of the resistant wild species,S. berthaultii. At each generation, selection was imposed for increased survival, decreased development time, and for increased fecundity. Although several parameters responded to selection, net replacement rate (R0) onS. berthaultii was consistently less than 1/3 that on cultivated potato. At the tenth generation, eachS. tuberosum strain female replaced herself with 110 daughters, whereas females from strains reared on PI 473334 and PI 473331 produced an average of 30 and 7 daughters, respectively. Slopes of the R0 regression lines for populations reared onS. tuberosum andS. berthaultii did not differ from zero, indicating no significant response to selection. Our findings suggest that populations of the Colorado potato beetle may have genetic variability in some performance traits for adaptation toS. berthaultii, but that adaptation is unlikely to occur as rapidly as previously reported.
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  • 35
    ISSN: 1572-8889
    Keywords: firefly ; entrainment ; insect communication ; Coleoptera ; aggressive mimicry ; bioluminescence ; Lampyridae
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    Notes: Abstract FemalePhoturis versicolor fireflies attempt to capture males by responding to heterospecific flash patterns. A mating-dependent switch occurs which affects response timing and frequency of female flashes. We examined the switch using females of known age, mating status, and flash experience to assess how accurate mimicry is, what factors influence it, and what mechanism produces it. Presentations of simulated male flash patterns before and after mating revealed elements of an entrainment mechanism controlling female responsiveness. Unmated females preferentially answered conspecific patterns with variable latencies, averaging 1 s. Mating induced changes in both response frequency and response latency: Females answered heterospecific patterns more frequently, and latencies elicited by conspecific patterns shifted away from the unmated range. Heterogeneity in mean and variance of response latency among individuals indicates that females do not share a discrete reply to a given pattern. Little correspondence exists between latencies of sympatric species andP. versicolor females, suggesting that the flash response mechanism produces entriainment to any rhythmic pattern, not a one-to-one matching between prey and predator latencies. Different selective scenarios underlie strict mimicry versus entrainment mimicry.
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    Journal of insect behavior 6 (1993), S. 715-735 
    ISSN: 1572-8889
    Keywords: Aphrodisiac ; cockroach ; evolution ; mating behavior ; sex pheromone ; sternal glands ; tergal glands
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    Topics: Biology
    Notes: Abstract Two chemical signals are essential in all cockroach sexual behavioral sequences: the sex pheromone released by one partner, generally the female (for long distance attraction), and an aphrodisiac sex pheromone produced exclusively by male tergal glands (for female mounting and tergal contact or “feeding” behavior). Unlike the other cockroach groups, the males of the Oxyhaloinae species produce both chemical signals: the pheromone and the aphrodisiac. The occurrence of three patterns of mating behavior (A, B, and C), the production of male sex pheromones, and the existence in the male of developed sternal and tergal glands in seven related Oxyhaloinae species, make these cockroaches a useful model for studying the evolution of mating behavior patterns. The various types of mating behavior were not classified in the previous studies by Roth and Barth. In this report, they have been named type A (female in upper position), B (male in upper position), and C (male and female end to end). In type A mating, the male tergal glands, which are licked by the females, are well developed, whereas in types B and C, there is no licking of the male's tergal secretion by the females and the tergal glands are much less developed; the aphrodisiacs secreted by the tergal glands may no longer act in this case through contact chemoreception, but through an olfactory process involving volatile components. One common sex pheromone component seems to be acetoin. I suggest that the mating behavior tends from A toward B and C during the evolutionary process with a concomitant regression of the tergal glands and changes in the aphrodisiac emission levels. The mating behavioral sequences of cockroaches (Dictyoptera) and crickets (Orthoptera) show a striking degree of similarity and are probably examples of convergent evolution.
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    Journal of solution chemistry 19 (1990), S. 1137-1151 
    ISSN: 1572-8927
    Keywords: Ethylbenzene ; excess entalphy ; excess volume ; experimental ; heat capacity ; isobaric expansibility ; isentropic and isothermal compressibility ; liquid mixtures ; mixing function ; n-alkanes ; n-hexadecane ; n-tetradecane ; pressure ; temperature ; theory
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Isobaric expansibilities α P and isothermal compressibilities κ T have been determined at 25 and 45°C for binary mixtures of ethylbenzene + n-tetradecane and + n-hexadecane and the corresponding excess functions (∂V E /∂T)P and (∂V E /∂P)T have also been obtained. With these data and supplementary literature values, the following second order mixing properties are also reported at 25°C: κ S E , (∂V E /∂P)T, ΔCV and Δ(ΔγVT). All mixing quantities have been compared with the results obtained at 25°C by using the Prigogine-Flory-Patterson theory of liquid mixtures. The predicted values suggest that the ability of ethylbenzene as a breaker of the pure n-Cn orientations is similar to what we found for toluene and higher than for p-xylene.
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  • 38
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    Journal of solution chemistry 23 (1994), S. 997-1018 
    ISSN: 1572-8927
    Keywords: Conductivity ; aqueous ; sodium chloride ; pressure ; ion association ; temperature
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Electrical conductance measurements of dilute (〈0.1 mol-kg−1) aqueous NaCl solutions were made primarily to quantify the degree of ion association which increases with increasing temperature and decreasing solvent density. These measurements were carried out at temperatures from 100 to 600°C and pressures up to 300 MPa with a modified version of the apparatus used previously in the high temperature study in this laboratory. Particular emphasis was placed on conditions close to the critical temperaturelpressure region of water, i.e., at 5° intervals from 370 to 400°C. The results verify previous findings that the limiting equivalent conductance Ao of NaCl increases linearly with decreasing density from 0.75 to 0.3 g-cm−1 and also with increasing temperature from 100 to 350°C. Above 350°C. Ao is virtually temperature independent. The logarithm of the molal association constant as calculated exclusively from the data≥400°C is represented as a function of temperature (Kelvin) and the logarithm of the density of water (g-cm−3) as follows: $$log K_m = 0.997 - 650.07/T - (10.420 - 2600.5/T)log\rho _w $$ Note that this function also provides a good representation of the log Km values obtained from 350 to 395°C at densities greater than ca. 0.6 g-cm−3. More precise conductance data now available in the literature suggest a systematic error of unknown origin may exist in the data obtained at lower densities in this region. The relevant thermodynamics quantities derived from differentiation of this equation with respect to temperature and pressure are listed in the text.
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  • 39
    ISSN: 1572-8889
    Keywords: Belostomatidae ; giant water bugs ; paternal care ; eggs ; reproduction ; behavior ; brooding ; evolution
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    Topics: Biology
    Notes: Abstract Males of the giant water bug Lethocerus medius(Guerin) typify their monobasic subfamily, the Lethocerinae, in that they do not brood eggs attached to their backs as do males of all members of the subfamily Belostomatinae. Exclusive male parental investment as expressed in the Belostomatinae is extremely rare behavior among animals, and evolution of the trait is obscure. Lethocerus mediusmales apparently remain with their mates through oviposition and are consistently found in attendance of eggs after the female has departed. This behavior may enhance paternity assurance at no cost in opportunity for polygyny. Two double clutches of eggs were found, from which we infer the potential for polygynous matings and shared parental investment. Male L. mediusbrood attended egg clutches above the surface of the water, where they may moisten them, shade them, and defend them against predation. Egg attendance/brooding by L. mediusand other Lethocerusspecies may represent a plesiomorphic state from which paternal back- brooding evolved in the Belostomatinae.
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  • 40
    ISSN: 1572-8889
    Keywords: Coleoptera ; Scarabaeidae ; Cotinis nitida (L.) ; beetle flight ; pheromone bioassay
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  • 41
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    Journal of solution chemistry 20 (1991), S. 805-816 
    ISSN: 1572-8927
    Keywords: Alkanes ; 1-chlorobutane ; compressibilities ; excess volume ; expansibilities ; heat capacities ; heat of mixing ; liquids ; pressure ; temperature
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Isothermal compressibilities KΥ and isobaric thermal expansion coefficients αp have been measured at 25 and 45°C for pure components and the following binary mixtures: 1-chlorobutane+normal alkanes (n-Cn) where n=6, 8, 10, 12, 14 and 16. With these results and other thermodynamic data from literature the next mixing quantities have also been reported: (∂V E/∂T)P, − (∂V)E/∂P)T, K S v , ∂H E/∂P)T, Δ(αpγVT and ΔCv. The obtained results have been compared at 25°C with the calculated values by using the Prigogine-Flory-Patterson theory of liquid mixtures. The theory predicts the excess volume VE and ∂V E/∂P)T values rather well, the C P E quite poorly, while for ∂V E/∂T)P and ∂V E/∂P)T it is only predicted the trend with the chain length of the n-alkane. The last two quantities show deviations between theoretical and experimental, slightly higher in systems with longer n-alkanes than for shorter ones. Our conclusion is that a nonrigid linear molecule, like 1-chlorobutane, has a low ability as a breaker of the pure n-Cn orientation correlations, in between that which we found for toluene and p-xylene and much smaller than for cyclohexane or benzene.
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  • 42
    ISSN: 1572-8927
    Keywords: Phosphate ; protonation ; temperature ; pressure ; calorimetry ; equilibrium constants ; enthalpy and entropy
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Flow calorimetry has been used to study the interaction of HPO 4 2− and H2PO 4 − with H+ in water at temperatures of 348.15 and 398.15 K and at pressures of 1.52 and 12.50 MPa. The protonations of HPO 4 2− and H2PO 4 − are exothermic and endothermic, respectively, under these experimental conditions. Under the conditions of this study, the effect of pressure on the enthalpy changes for both reactions is small. Equilibrium constant K, enthalpy change ΔH, and entropy change ΔS values are given for the protonation reactions at each temperature. These values are compared with those reported in the literature. Incorporation into the calculation procedure of reactions involving association between protonated phosphate species to form hydrogen-bonded dimers does not result in better fits of the experimental data.
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  • 43
    ISSN: 1572-879X
    Keywords: EXAFS ; Pt/Al2O3 catalyst ; temperature ; pressure ; carbon deposition ; carbon removal
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    Topics: Chemistry and Pharmacology
    Notes: Abstract EXAFS has been used to follow in situ the structural evolution of a Pt/Al2O3 catalyst during removal of carbon by hydrogenation, after reduction and carbon deposition. After reduction at 350 °C, the total hydrogen pressure was raised to 3 atm. and n-heptane was injected over the sample. EXAFS measurements at the Pt edge were carried out with simultaneous on-line EXAFS analysis of the spectra. After observing the rapid formation of a carbon-platinum bond which is unmodified with time, we stopped the heptane flow, raised the temperature to 450 °C, and maintained hydrogen flow at 3 atm. The disappearance of the platinum-carbon bond during heat treatment in hydrogen was monitored via on-line analysis. No sintering of the metal particles was observed. EXAFS is thus proven to be an efficient tool to study not just structural changes of a catalyst during a hydrocarbon reaction [1], but also to use it as a technique to study other catalytic phenomena as well.
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  • 44
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    Entomologia experimentalis et applicata 59 (1991), S. 75-78 
    ISSN: 1570-7458
    Keywords: Leptinotarsa decemlineata Say ; Coleoptera ; Chrysomelidae ; female sex pheromone ; screening method ; mating behaviour ; tactile stimuli
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  • 45
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    Entomologia experimentalis et applicata 54 (1990), S. 219-224 
    ISSN: 1570-7458
    Keywords: Diabrotica virgifera virgifera ; Coleoptera ; Chrysomelidae ; corn ; life-stage occurrence ; planting date
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    Topics: Biology
    Description / Table of Contents: Résumé Dans les conditions de l'est du Sud Dakota (USA), 3 dates de semailles de maïs et 3 dates de contamination avec des œufs de D. virgifera virgifera LeConte ont servi à imposer ou à empêcher la synchronisation des éclosions des œufs et par conséquent des développements ultérieurs. Les dates médianes d'apparition de chacun des 3 stades larvaires et des imagos ont été déterminées en relation avec les unités de température et le nombre de jours depuis la contamination. Aucune différence significative entre les dates médianes d'apparition n'a été mise en évidence par utilisation des unités de température; par contre, ces différences deviennent significatives lorsque l'on utilise le nombre de jours depuis la contamination. Des paramètres fiables sont nécessaires pour prédire la présence des différentes stades de cet insecte. En dépit des différentes conditions imposées pour cette étude, la méthode la moins capricieuse pour prédire l'apparition d'un stade larvaire et l'émergence des adultes est la somme de températures avec une base de 11°C.
    Notes: Abstract Under field conditions in eastern South Dakota, USA three different planting dates of corn and three times of egg infestation were used to imposed synchronous and asynchronous timing of corn growth and Diabrotica virgifera virgifera LeConte egg hatch and subsequent development. Median occurrence of each of the three larval stages and of the adult stage for each of the infestation-planting treatments was determined by relating occurrence to thermal units and to days after infestation. No significant differences were found among the treatments for median occurrence of each life stage when the thermal unit approach was used. However, significant differences were found among treatments for median occurrence when the day after infestation approach was used. Consistent parameters are needed for prediction of the occurrence of life stages of this insect. Despite the various imposed conditions, this study indicates that the least variable method of predicting life stage occurrence and adult emergence of D. v. virgifera was the use of thermal unit accumulations (base 11°C).
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  • 46
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    Entomologia experimentalis et applicata 68 (1993), S. 9-13 
    ISSN: 1570-7458
    Keywords: bioassay ; behavioural response ; Coleoptera ; carob extract ; stored product
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    Topics: Biology
    Notes: Abstract The behavioural responses ofCryptolestes pusillus Oryzaephilus surinamensis andProstephanus truncatus to different doses of carob extract were assessed in a two-choice pitfall bioassay and in plastic grain probe traps. The extract evoked a quick directional response and induced high beetle attraction to treated pitfall arenas compared with the controls. Overall, the extract improved probe trap efficiency by about 50% compared to unbaited probes. Beetle response was dose-dependent with the medium dose of 10 μl probably eliciting optimum response.
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  • 47
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    Entomologia experimentalis et applicata 60 (1991), S. 143-155 
    ISSN: 1570-7458
    Keywords: Thrips obscuratus ; Thysanoptera ; Thripidae ; New Zealand flower thrips ; rearing ; oviposition rate ; development time ; temperature ; diet ; pollen
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    Topics: Biology
    Notes: Abstract The life history of New Zealand flower thrips (Thrips obscuratus (Crawford), Thysanoptera: Thripidae) was studied using a simple laboratory rearing method. The effects of temperature and diet on oviposition rate and development time were examined. Oviposition rate increased with increasing temperature between 10°C and 25°C. Development time for individual instars and for total development decreased with increasing temperature between 10°C and 27°C. Total development time ranged from 50 days at 10°C (female) to 10 days at 27°C (male). The relationship between temperature and development rate was expressed as a straight line such that lower thresholds of development of between 4.2°C and 6.3°C were established for life stages. Adult lifespan increased with decreasing temperature between 10°C and 25°C and females lived longer than males. At 10°C and 25°C females lived for an average of 34 and 3 weeks respectively. Thrips supplied with pollen exhibited highest and sustained levels of egg production in comparison to other diets. Larval mortality was lowest and development time fastest on diets of pollen and sucrose or fruit juice in comparison to other plant tissues. Larval development time was similar on four species of pollen.
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  • 48
    ISSN: 1572-879X
    Keywords: EXAFS ; Pt/Al2O3 catalysts ; chlorine ; temperature ; pressure ; reduction ; deactivation
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    Topics: Chemistry and Pharmacology
    Notes: Abstract EXAFS has been used to follow in situ the structural evolution of a chlorinated and non-chlorinated Pt/Al2O3 catalyst during reduction in the temperature range of 300–500 °C. Smaller metal clusters are formed from the hydrogen reduction of the chlorinated catalyst, in contrast to the larger cluster formed from the non-chlorinated one. At 460 °C, the total hydrogen pressure was raised to 5 atm. and n-heptane was injected over the samples. EXAFS measurements at the Pt edge were carried out while hydrocarbon conversion was monitored with a gas Chromatograph. We observe the rapid formation of a carbon-platinum bond. This is unmodified while turnover rates and selectivities indicate evidence for deactivation. From this structural information supplied by EXAFS, correlated with the data obtained from gas chromatography, we find that our results are consistent with a model proposed by others where deactivation is due to the build-up of a multilayer of carbon.
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  • 49
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    Cellular and molecular life sciences 46 (1990), S. 457-458 
    ISSN: 1420-9071
    Keywords: Rat ; carnitine ; lipolysis ; exercise ; glycogen ; triglycerides ; muscle
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    Topics: Biology , Medicine
    Notes: Summary To test the effect of L-carnitine on glycogen sparing when fat oxidation is increased, 100 mg/kg/d were given to rats orally for 3 days, resulting in 1.8-fold higher muscle carnitine levels. Even when FFA were raised by heparin-stimulated lipolysis, the rate of glycogen degradation was not reduced during exercise.
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  • 50
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    Cellular and molecular life sciences 46 (1990), S. 700-704 
    ISSN: 1420-9071
    Keywords: Coleoptera ; Tenebrionidae ; Tribolium confusum ; defesive secretion ; biosynthesis of 1-alkenes ; oxidative decarboxylation ; anti-elimination
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    Topics: Biology , Medicine
    Notes: Summary The terminally unsaturated hydrocarbons of the defensive secretion ofTribolium confusum are biosynthesized from fatty acids by oxidative decarboxylation. The process involves an enantiospecific cleavage of the C−H bond of thepro-(S) C(3)−H atom and simultaneous decarboxylation of the acid into an 1-alkene and carbon dioxide via ananti-periplanar transition state geometry (anti-elimination). The stereochemistry of this biotranformation is identical in all respects with the same reaction in higher plants. The mechanism seems to be of general importance for the biosynthesis of many vinylic substructures of natural products from oxygen-containing precursors.
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  • 51
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    Cellular and molecular life sciences 49 (1993), S. 171-174 
    ISSN: 1420-9071
    Keywords: Coleoptera ; Meloidae ; Epicauta funebris ; chemical defense ; biosynthesis ; terpenoid
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    Topics: Biology , Medicine
    Notes: Abstract Cantharidin, a potent defensive chemical, is present in all ten life stages of the blister beetleEpicauta funebris. The first five larval stages accumulate cantharidin as they feed and grow in size. When disturbed, they exude cantharidin in a milky oral fluid, not in hemolymph which adult beetles reflexively discharge from leg joints. Two subsequent larval stages and the pupa do not feed, grow, regurgitate, or change in their defensive reserves (110 μg cantharidin/insect, regardless of sex). Adult beetles kept in isolation for 60–90 d exhibit a pronounced sexual dimorphism in cantharidin production: the male biosynthesizes about 17 mg of the toxin, representing 10% of his live weight, whereas the female actually loses most of her defensive reserves. But in the wild a female beetle repeatedly acquires cantharidin as copulatory gifts from her mates.
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  • 52
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    Cellular and molecular life sciences 49 (1993), S. 272-275 
    ISSN: 1420-9071
    Keywords: Semiochemical ; pheromone ; host selection ; competition ; Coleoptera ; Scolytidae
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    Topics: Biology , Medicine
    Notes: Abstract Bark beetles,Ips typographus andPityogenes chalcographus, attracted by synthetic or natural pheromone to Norway spruce logs,Picea abies, preferred to colonize uninfested logs rather than logs occupied by these beetles, probably as a means of avoiding intra-and interspecific competition. The aggregation pheromone components ofP. chalcographus, chalcogran and methyl (E, Z)-2,4-decadienoate, inhibited the attraction response ofI. typographus to its pheromone components (methyl butenol andcis-verbenol), while the converse was not true. However, verbenone released from colonized bark inhibited pheromonal response ofP. chalcographus.
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  • 53
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    Cellular and molecular life sciences 50 (1994), S. 521-523 
    ISSN: 1420-9071
    Keywords: Ancient DNA ; evolution ; conservation ; biology ; anthropology ; plant biology ; PCR (polymerase chain reaction)
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  • 54
    ISSN: 1420-9071
    Keywords: Insect ; behaviour ; high-speed cinematography ; jumping ; electrophysiology ; evolution
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    Notes: Abstract The Indian antHarpegnathos saltator may be unique among insects in using its jumping capacity not only as an escape mechanism but also as a normal means of locomotion, and for catching its prey in flight. High-speed cinematography used to analyse the various phases of the jump suggests thatHarpegnathos employs a novel jumping mechanism to mediate these behaviours: namely the synchronous activation of its middle and hindlegs. Electrophysiological recordings from muscles or nerves in pairs of middle and hindlegs show remarkably synchronous activity during fictive jumping, supporting the synchronous activation hypothesis.Harpegnathos is not the only ant to jump, and a cladistic analysis suggests that jumping behaviour evolved independently three times during ant evolutionary history.
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  • 55
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    Cellular and molecular life sciences 46 (1990), S. 1106-1117 
    ISSN: 1420-9071
    Keywords: Genetic code ; eucaryotic cell ; evolution ; code ambiguity ; code universality ; convergence
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    Topics: Biology , Medicine
    Notes: Summary This article is a review of the rules used by eucaryotic cells to translate a nuclear messenger RNA into a polypeptide chain. The recent observation that these rules are not identical in two species of a same phylum indicates that they have changed during the course of evolution. Possible scenarios for such changes are presented.
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  • 56
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    Cellular and molecular life sciences 49 (1993), S. 1027-1036 
    ISSN: 1420-9071
    Keywords: Archaea (archaebacteria) ; extreme halophiles ; archaeol phospholipids ; archaeol glycolipids ; membrane function ; evolution
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    Topics: Biology , Medicine
    Notes: Abstract Archaebacteria (archaea) are comprised of three groups of prokaryotes: extreme halophiles, methanogens and thermoacidophiles (extreme thermophiles). Their membrane phospholipids and glycolipids are derived entirely from a saturated, isopranoid glycerol diether,sn-2,3-diphytanylglycerol (‘archaeol’) and/or its dimer, dibiphytanyldiglyceroltetraether (‘caldarchaeol’). In extreme halophiles, the major phospholipid is the archaeol analogue of phosphatidylglycerolmethylphosphate (PGP-Me); the glycolipids are sulfated and/or unsulfated glycosyl archaeols with diverse carbohydrate structure characteristic of taxons on the generic level. Biosynthesis of these archaeol-derived polar lipids occurs in a multienzyme, membrane-bound system that is absolutely dependent on high salt concentration (4 M). The highly complex biosynthetic pathways involve intermediates containing glycerol ether-linked C20-isoprenyl groups which are reduced to phytanyl groups to give the final saturated polar lipids. In methanogens, polar lipids are derived both from archaeol and caldarchaeol, and thermoacidophiles contain essentially only caldarchaeol-derived polar lipids. The function of these membrane polar lipids in maintaining the stability, fluidity and ionic properties of the cell membrane of extreme halophiles, as well as the evolutionary implications of the archaeol and caldarchaeol-derived structures will be discussed.
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  • 57
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    Cellular and molecular life sciences 48 (1992), S. 729-731 
    ISSN: 1420-9071
    Keywords: Urea cycle ; leech ; botryoidal tissue ; hirudineans ; evolution
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    Topics: Biology , Medicine
    Notes: Abstract Ornithine carbamoyltransferase (OCT) and arginase, but not arginine synthetase (AS), were detected in the body wall and gut tissues of the leech. The activities of these enzymes were not altered by starvation. The high activity of arginase in body wall is probably due to the association of the latter with botryoidal tissue. Hirudineans, which evolved from oligochaete ancestors, appear to have lost the citrulline-arginine segment of the urea cycle due to their ammonotelic mode of nitrogen excretion.
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  • 58
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    Cellular and molecular life sciences 50 (1994), S. 987-1001 
    ISSN: 1420-9071
    Keywords: Hsp70 ; evolution ; gene duplication ; gene homology
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    Topics: Biology , Medicine
    Notes: Abstract The family of genes encoding heat shock proteins of about 70 kDa (hsp70) in vertebrates is reviewed under genetic aspects. After a detailed description of the various hsp70 genes more general characteristics of the organization and evolution of the multigene family are discussed.
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    Cellular and molecular life sciences 49 (1993), S. 317-319 
    ISSN: 1420-9071
    Keywords: Chitin ; cuticle ; evolution ; vertebrates ; bony fish ; Blenniidae ; Paralipophrys trigoides
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    Topics: Biology , Medicine
    Notes: Abstract Lectin binding, endo-chitinase binding and enzymatic degradation studies show that the epidermal cuticle of the bony fishParalipophrys trigloides (Blenniidae) is chitinous. This is the first evidence that a vertebrate species possesses a chitinous tissue. Recently aXenopus gene has been identified which has significant sequence similarity to the catalytic domain of yeast chitin synthase III, a chitin producing enzyme1,2. Taken together these two findings imply that chitin synthesis capability may be a basic vertebrate feature.
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    Cellular and molecular life sciences 50 (1994), S. 429-437 
    ISSN: 1420-9071
    Keywords: Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
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    Entomologia experimentalis et applicata 56 (1990), S. 15-21 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; corn rootworms ; age-specific survival ; age-specific fecundity
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    Topics: Biology
    Description / Table of Contents: Résumé D. virgifera virgifera LeConte a été placé sur des régimes nutritifs mimant l'évolution des tissus du maïs disponsibles dans le champ lorsque les insectes éclosent est aux stades suivants du maïs: 1) après émergence de l'épi mâle, mais avant l'apparition des barbes et l'émission du pollen; 2) lors de la présence de barbes et de l'émission de pollen; 3) après la pollinisation et quand les barbes ont bruni. Un quatrième régime a été fourni pendant toute l'expérience comprenant des barbes vertes, du pollen et des feuilles. Les pontes moyennes des femelles pendant les 12 semaines de l'étude on été 125, 235, 179 et 441 pour les régimes 1, 2, 3 et 4. Les dates de mort de la moitié des adultes a été 7,2, 7,2, 6,7 et 8,8 semaines pour respectivement les mêmes régimes. Les femelles du régime 1 pondent à un âge plus avancé que les femelles des régimes 2 et 3. L'influence des changements de la qualité alimentaire du maïs au fur et à mesure du vieillissement des plantes et deDiabrotica, a été déterminée par la survie au bout de 48 heures d'insectes éclos depuis peu et d'autres maintenus en cage sur des lots de maïs à différents stades poussant en serre depuis des temps plus ou moins longs. Plus les plantes sont âgées, plus la survie des 2 groupes deDiabrotica diminue, mais plus vite chez les lots d'insectes âgés.
    Notes: Abstract Adult corn rootworm beetles,Diabrotica virgifera virgifera LeConte, were maintained on three dietary regimes which mimicked the progression of corn tissues that would be available in the field for beetles eclosing when corn was in the following growth stages: (A) after tassels had emerged but prior to silking and pollen shed; (B) while plants were silking and shedding pollen; and (C) after pollination was complete and silks had turned brown. A fourth regime (D) was established in which green corn silks, pollen, and leaves were provided throughout the study. The mean number of eggs laid per female over the 12-week duration of the study was 125, 235, 179, and 441 for regimes A, B, C, and D, respectively. Median length of life was 7.2, 7.2, 6.7, and 8.8 weeks for regimes A, B, C, and D respectively. Beetles in regime A laid a greater proportion of their eggs at an older age than did beetles from regimes B and C. To further investigate the influences on survival of changes in food quality of corn as plants and beetles aged, newly-eclosed beetles and beetles that had been maintained in caged plots of corn growing in a greenhouse for various lengths of time were caged on corn at different stages of growth, and the proportion of beetles surviving for 48 h was determined. Survival decreased as plants aged for both groups of beetles, but decreased at a faster rate for old than for young beetles.
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  • 62
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    Journal for general philosophy of science 21 (1990), S. 231-257 
    ISSN: 1572-8587
    Keywords: basic rules ; change ; discipline-neutral ; evolution ; analogy
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    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary A small step is made in the direction of defining some general basic rules which can serve as a framework for research in several fields of the social sciences. The method of working with analogies asks for a more accurate approach. Starting from the concept of evolution in the form of a basic rule another basic rule is formulated. This rule shows what are the most important factors in long term developments and what types of development one can expect.
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    Journal for general philosophy of science 22 (1991), S. 133-141 
    ISSN: 1572-8587
    Keywords: evolution ; teleology ; chance ; purpose ; anthropomorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary Revaluation of the problem of natural teleology seems an important precondition for elucidating our environmental crisis and for formulating an ‘ecological ethics’, because it calls for a recognition of an intrinsic value in nature and organisms. Therefore, it is necessary to show that the concept of natural teleology is not in contradiction with scientific theories, in particular not with the theory of evolution. In this paper I shall argue that there is a fundamental misunderstanding about the concepts of teleology and chance in modern thinking. This as a result of a radical transformation of the Aristotelian concept of teleology by Christian theologians during the Middle Ages. This confusion resulted in the rejection of teleology from evolution and in an exaggeration of the role of chance. However, not a solution for the problem of teleology is given here, but only an attempt to prove that neither the fossil-record, nor the role of chance in evolution can give adequate arguments for the negation of teleology in evolution. That is not to say that, therefore there exists teleology in evolution, but the problem of teleology in nature cannot, be solved by the scientific theory of evolution, but only be elucidated by philosophical analysis. At the end of the paper it is argued that teleology must be rather presupposed in evolution.
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  • 64
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    Journal for general philosophy of science 23 (1992), S. 85-103 
    ISSN: 1572-8587
    Keywords: life ; teleology ; evolution ; reality ; representation ; experience
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary A comprehensive definition of the phenomenon called “life” led to the addition of many dimensions to the natural sciences, and especially the conscious mental dimension. Historical attention is paid not only to those employing the natural philosophical paradigms, but also to evolutionary theories and to the Kantian teleological philosophy. The belief that science can solve the riddle of life is a category of purposal thinking. A revised version of critical teleology is essential for comprehension of life.
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  • 65
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    Entomologia experimentalis et applicata 59 (1991), S. 59-66 
    ISSN: 1570-7458
    Keywords: Bruchidae ; adult polymorphism ; temperature ; hygrometric factors ; reproductive quiescence ; population dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Callosobruchus maculatus (F.) est un Coléoptère Bruchidae tropical qui se développe aux dépens des graines de Vigna unguiculata. Les adultes présentent un polymorphisme; il y a en effet deux formes, la forme voilière et la forme non voilière, distinctes par des critères morphologiques, physiologiques et comportementaux. L'évolution des populations de C. maculatus a été suivie pendant toute la saison sèche et le début de la saison des pluies dans la région de Niamey au Niger (13° LN) à l'intérieur d'un grenier traditionnel. Pendant toute la saison sèche, 6 à 7 générations de C. maculatus de la forme non voilière se succèdent à l'intérieur du grenier. Les adultes de la forme voilière, très actifs, apparaissent surtout au cours de la saison des pluies lorsque la teneur en eau de l'atmosphère et la teneur en eau des graines augmentent. Les études expérimentales réalisées au laboratoire montrent que le polymorphisme imaginal est induit au cours du développement post-embryonnaire et dépend des conditions climatiques dans lesquelles celui-ci a lieu. Le taux d'adultes de la forme voilière est élevé lorsque les larves se développent dans des graines à forte teneur en eau (14 ou 15%). Lorsque la teneur en eau des graines est faible (6 à 7%), il n'y a émergence que d'adultes de la forme non voilière. Lorsque la teneur en eau des graines est comprise entre 12 et 13%, le taux d'adultes de la forme voilière s'accroit et varie avec la durée de la thermophase. A basse température il y a toujours émergence d'adultes de la forme non voilière, quelle que soit la teneur en eau des graines. L'influence de ces deux facteurs abiotiques sur l'induction du polymorphisme imaginal joue probablement un rôle important dans les mécanismes adaptatifs permettant le maintien de cette espèce en zone tropicale.
    Notes: Abstract Callosobruchus maculatus (F.) is a tropical insect (Coleoptera: Bruchidae) that develops in Vigna unguiculata (Walp) seeds. In this beetle, there are two distinct adult forms that differ in their morphology, physiology and behaviour, the flight form and the flightless form. The development of C. maculatus is analyzed in a traditional store in Niger. During the dry season, 6 to 7 generations of the flightless form develop in the store. When the atmospheric water content increases during the rainy season, adults of the flight form appear and escape from the store. Experimental studies have shown that the adult polymorphism is induced during post-embryonic development and depends on prevailing abiotic factors during this period. The proportion of flight from adults is high when larvae develop in moist seeds (14–15% of water content). Under dry conditions (6–7% of water content) only flightless adult forms emerge from the seeds. Temperatures during development also influence adult polymorphism. In thermoperiodic conditions with 12–13% seed water content, the proportion of flight from adults increases with increasing duration of the thermophase. However, at low temperatures, a high proportion of flightless adult forms emerge, regardless of seed water content. The adaptive importance of these two abiotic factors on polymorphism induction is examined in this study.
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  • 66
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    Entomologia experimentalis et applicata 61 (1991), S. 255-263 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Bruchidae ; Bruchidius atrolineatus ; larval crowding ; post-embryonic development ; intracotyledonary mortality ; weight of emerging adults ; reproductive diapause
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Chez Bruchidius atrolineatus, l'accroissement de la densité larvaire à l'intérieur de la graine entraîne une augmentation de la mortalité alors que la réduction de poids des individus à l'émergence est relativement limitée. L'accroissement de la densité larvaire provoque une augmentation du taux d'adultes en diapause reproductrice, dans certaines conditions thermopériodiques. Dans d'autres conditions, permenttant l'émergence d'un fort taux d'adultes diapausants, l'effet de la densité larvaire est nul. Lorsque l'on analyse l'effet de la densité chez les individus d'une souche ne présentant pas de phénomène de diapause, il n'y a pas de corrélation entre la durée de développement et le poids des adultes. Par contre, lorsqu'il y a émergence d'adultes sexuellement actifs et diapausants, il existe une corrélation entre la durée de développement et le poids des adultes émergeants. Cette corrélation est due au fait que les adultes diapausants, qui présentent les durées de développement les plus longues, sont ceux qui ont les poids les plus faibles.
    Notes: Abstract In Bruschidius atrolineatus (Pic), an increase in larval density inside the seed led to a reduction in the survival rate during post-embryonic development, with only a limited decrease in the weight of adults. A high larval density increased the proportion of adults in reproductive diapause under certain thermoperiodic conditions. Under other conditions that already promote the emergence of a high proportion of diapausing beetles, an increase in larval density had no effect on diapause. There was no correlation between the larval developmental time and the weights of adults in a strain with a very low incidence of diapause. However, such a correlation was observed when both sexuallyactive and diapausing beetles emerged. This correlation was explained by the longer developmental times and lower weights of diapausing beetles.
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    Entomologia experimentalis et applicata 66 (1993), S. 3-12 
    ISSN: 1570-7458
    Keywords: evolution ; coevolution ; selection ; insect attack ; plant defense ; competition ; enemy free space ; chemoreception ; specialization ; plant recognition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Most hypotheses concerning the evolution of insect-plant relationships are based on the assumptions that, (1) phytophagous insects reduce plant fitness, and that (2) insect-plant relationships are the result of unconstrained selection. It can be shown, however, that there is little evidence to support these assumptions. As an alternative, it is proposed that the evolution of insect-plant relationships results primarily from autonomous evolutionary events; namely from heritable functional changes within the insects' nervous system that determine plant recognition and ultimately host plant specificity. These changes cannot be evoked by selective ecological agents. They originate from intrinsic changes (mutationssensu lato) within the insect genome. Ecological factors play a secondary role: by either supporting or preventing the establishment of the new genotype with the novel food preference.
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    Entomologia experimentalis et applicata 55 (1990), S. 161-168 
    ISSN: 1570-7458
    Keywords: Tephritidae ; Dacus oleae ; olive fruit fly ; ovarian maturation ; olive fruit ; diapause ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La maturation ovarienne des femelles adultes agées de 7, 22–23 et 28 jours de D. oleae ayant accompli leur développement embryonnaire, larvaire et nymphal en LD 12:12, 19±1°C et maintenues en LD 16:8, 26±1°C, sans accès à des olives, est inhibée. Dans les mêmes conditions, mais avec accès permanent à des olives, 54% des femelles ont des ovocytes mûrs à 7 jours, 87% à 22–23 jours et 100% à 28 jours. Avec des femelles ayant accès à des domes de paraffine, les pourcentages d'individus ayant des ovocytes mûrs sont intermédiaires entre ceux des deux situations précédentes. Dans les conditions cidessus défavorables à la maturation ovarienne, 50% des femelles de 28 jours ont des ovocytes mûrs si elles sont en présence d'olives durant leur première semaine de vie imaginale et 91% si elles sont en présence la 4éme semaine. Les pourcentages respectifs concernant les femelles pourvues de dômes de paraffine sont encore intermédiaires entre ceux des femelles avec olives et ceux de femelles privées de tout substrat. La présence d'olives a aussi un effet fortement positif sur la maturation ovarienne de femelles ayant accompli leur développement pre-imaginal et maintenues aussi à l'etat adulte en conditions LD 16:8, 26±1°C, favorisant la maturation ovarienne. L'accès à des dômes de paraffine a, là encore, un effet intermédiaire. On conclut par conséquent que la non maturation ovarienne des femelles de D. oleae qui est causée par une photopériode à jour court pendant la vie pre-imaginale accompagné par une photopériode à jour long et une augmentation de la température pendant la vie imaginale persiste au moins jusqu'à la fin de la quatrième semaine de la vie imaginale en absence d'olives, mais ne se produit pas si on met les femelles adultes en présence d'olives.
    Notes: Abstract Ovarian maturation was prevented in 7-, 22-, 23- and 28-day-old females of Dacus oleae (Gmelin) (Diptera: Tephritidae), developed in the pre-imaginal stages at LD 12:12, 19±1°C and kept as adults at LD 16:8, 26±1°C without access to olive fruits. In females of the above ages having continuous access to olive fruits and held under the same photoperiod and temperature conditions, 54, 87 and 100%, respectively, had mature oocytes. When the females had access to domes of paraffin wax, the percentages of females with mature oocytes were intermediate between those with and those without access to olive fruits. Under the above photoperiod and temperature conditions unfavorable for maturation, 50% of 4-week-old females had mature oocytes if exposed for one week to olive fruits during their first week and 91% if exposed during their 4th week of adult life. The respective percentages with wax domes in the cages were again intermediate between those with olives and those without olives or wax domes. The presence of olive fruits had also a strong positive effect on the ovarian maturation of females which developed from egg through the adult stage at LD 16:8, 26±1°C, a condition favoring ovarian maturation. Access to wax domes had again an intermediate effect on maturation. It is concluded therefore that the lack of ovarian maturation of D. oleae females which is observed under a short photophase during the pre-imaginal stages if followed by a long photophase and an increase of temperature during the adult stage, continues at least till the end of the 4th week of adult life in the absence of olive fruits but is averted when such fruits are offered to the adult flies.
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  • 69
    ISSN: 1570-7458
    Keywords: Cryptomyzus ; aphid ; hybridization ; host plant preference ; reproductive performance ; host-alternation ; speciation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé C. galeopsidis Kaltenbach contient plusieurs formes qui ont différentes relations avec des plantes hôtes et des cycles distincts. Des croisements ont permis d'élucider la taxonomie de ces formes et d'étudier l'hérédité de préférences d'hôtes, des performances reproductives et de l'alternance d'hôtes. Une des formes apparaît comme une espèce distincte par suite de la valeur adaptative réduite des hybrides. Les autres formes avec alternance ou non des hôtes sont considérées comme conspécifiques et représentant deux stratégies vitales différentes. Les performances reproductives sont probablement polygéniques puisque les hybrides ont des performances intermédiaires. Les préférences d'hôtes des hybrides montrent certains degrés de dominance et semblent déterminées par quelques gènes seulement. L'alternance des hôtes est envisagée comme ayant une hérédité monofactorielle. Les conséquences sur la spéciation sont discutées.
    Notes: Abstract The aphid species Cryptomyzus galeopsidis (Kaltenbach) includes several distinct forms which have different host plant relationships and life cycles. Cross breeding was used to elucidate the taxonomic status of these forms and to investigate the inheritance of host preference, reproductive performance and host-alternation. One of the forms appeared to be a distinct species because of the reduced fitness of the hybrids. Other host-alternating and non host-alternating forms are considered conspecific and represent two life cycle strategies. Reproductive performance is probably controlled polygenically, since hybrids show an intermediate performance. Host preference in hybrids showed some degree of dominance and seemed to be determined by only a few genes. Host-alternation is presumed to be inherited monofactorially. The implications for speciation are discussed.
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    Calcified tissue international 50 (1992), S. 524-526 
    ISSN: 1432-0827
    Keywords: Verapamil ; Bone ; Osteopenia ; Rat ; Female ; Intestinal calcium absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Verapamil inhibits the intestinal absorption of calcium (Ca) and increases serum parathyroid hormone in rats. The effects of verapamil on bone tissue after long-term treatment is, however, not well described. Adult female and male Sprague-Dawley rats received verapamil in their drinking water at a dosage of 0.075 mg/ml (low dose) or 0.75 mg/ml (high dose) for 12 weeks; control rats received only drinking water. All rats were fed a diet containing 0.1% Ca and 0.5% P. In female rats, the amount of bone ash per volume was significantly reduced from 0.742 g/ml in controls to 0.713 g/ml after low-dose treatment of verapamil, and to 0.667 g/ml following high-dose treatment (P〈0.01). The tibial length was increased from 39.7 mm in controls to 40.3 mm or to 40.7 mm after low or high doses (P〈0.01). The tibial volume increased from 0.385 ml in controls to 0.397 ml after low doses and to 0.429 ml after high doses (P〈0.01). In contrast, in male rats the amount of bone ash per volume was significantly increased from 0.578 g/ml in controls to 0.580 g/ml after low doses and to 0.620 g/ml after high doses of verapamil (P〈0.01). The tibial bone volume in males as decreased from 0.633 ml in controls to 0.641 ml after low doses and to 0.583 ml after high doses (P〈0.05). The tibial length in the males was not changed by verapamil. The intestinal absorption of Ca was reduced in male rats from 5.28 in controls to 4.03 (serosa/mucosa) after low-dose treatment and to 2.46 after high-dose treatment with verapamil (P〈0.05). In female rats, the intestinal absorption of Ca did not change after verapamil treatment. Thus, chronic treatment with verapamil in female rats induced osteopenia whereas in male rats bone growth was inhibited.
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  • 71
    ISSN: 1432-0827
    Keywords: Rat ; Osteoblast-like culture ; Ovariectomy ; Estrogens ; Bone blood supply
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Ovariectomy in the rat induces a rapid osteopenia associated with an elevated bone turnover. One hundred and twenty-day-old rats were ovariectomized (OVX) or sham-operated (n=6–8 per group and per time period studied). 45Ca accretion rate and bone blood flow (microspheres trapping technique) in the femurs were determined at 28, 42, 84, and 119 days after ovariectomy. Both parameters were markedly increased by 84 days and subsided thereafter. At the 42nd day, when bone turnover was maximal, bone marrow and trabecular bone cultures were obtained from shamoperated and ovariectomized animals (n=10/group). Proliferation rate of bone marrow cells and trabecular osteoblast-like cells estimated by fibroblast colony-forming units (FCFU) efficiency and cell counting was markedly increased in primary and secondary cultures in ovariectomy. These data fitted well with the enhanced number of osteoblasts observed in situ in the long bone metaphyses of estrogen-depleted animals. As estrogens were shown in the literature to inhibit proliferation of the red cell line and of other hemopoietic lines, it is possible that estrogens, through a general mechanism, inhibit hemopoietic and stromal lines and also the proliferation of bone marrow-derived trabecular bone cells.
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    Calcified tissue international 52 (1993), S. 361-364 
    ISSN: 1432-0827
    Keywords: Calcitonin ; Sustained release ; Copolymer depot ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Studies were carried out to determine whether monolithic depot formulations, prepared using lactide:glycolide copolymers, could be used to administer salmon calcitonin (sCT) to rats in vivo. Formulations containing 2, 5, or 10% (w/w) sCT were administered subcutaneously to female Wistar strain rats. Release of sCT was determined by measurement of peptide in plasma using a specific radioimmunoassay and by measurement of residual sCT in the depots after recovery at postmortem. Plasma calcium concentrations and cumulative weight gain of the animals were used to measure pharmacological effects of the released sCT. Release of sCT from the depots was controlled by the copolymer and was sustained for periods up to 10 days. However, the release of sCT from the depots did not significantly alter plasma calcium concentrations, and effects on cumulative weight gain were small and transient. Peptide loading of the formulations was shown to modify sCT release. Maximal release of sCT from depots containing 10% peptide occurred over a 7 to 14-day period postadministration, with 5% sCT release occurred between days 11 and 14, and with 2% sCT, the period of maximal release was between days 11 and 18. Release of peptide from the depots was essentially complete by 21 days postadministration irrespective of the peptide loading. These data suggest that lactide:glycolide copolymer depots may have application for the convenient clinical administration of sCT in metabolic bone diseases.
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  • 73
    ISSN: 1432-0827
    Keywords: Bone ; Nandrolone decanoate ; Ovariectomy ; Bone mechanics ; IGF-I ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Nandrolone decanoate (ND) is an anabolic steroid with a positive effect on bone mass in osteoporotic patients. The mechanism of action, (i.e., reduction of bone resorption and/or Stimulation of bone formation), the ultimate effect on mechanical properties, and the most effective dosage are not yet clear. To address these issues, dose-related effects of the long-term effect of ND on Serum and bone biochemistry, bone mineral content, and bone mechanical properties in ovariectomized (OVX) rats (12 weeks old at the Start of the experiment) were Studied for 6 months. The results were compared with those obtained in agematched, intact, and OVX rats. OVX caused in the femur a significant increase in net periosteal bone formation and net endosteal bone resorption of bone collagen content and torsional strength, and of Serum alkaline phosphatase, osteocalcin, and insulin-like growth factor-I (IGF-I) levels, whereas cortical bone density and calcium/creatinine and phosphorus/creatinine in 24-hour urine were Significantly reduced. Treatment of OVX rats with 1 mg ND/14 days resulted in a Significant increase in periosteal bone formation, femur length, cortical and trabecular bone mineral content and density, torsion stiffness and Strength, and bone IGF-I content, and a decrease in Serum osteocalcin, urinary calcium/creatinine levels, and bone collagen content compared with OVX controls. The higher ND dosage of 2.5 mg/14 days did not improve the results. ND treatment did not reverse all changes induced by OVX to the level of the intact controls. These results indicate that ND acts as an antiresorptive drug and as a bone formation Stimulating drug. Furthermore, the increased bone mass and bone mineral density is associated with improved bone Strength and stiffness and the presence of an increased amount of IGF-I. IGF-I is a growth factor considered to play a role in the maintenance of normal skeletal balance by a paracrine or autocrine mechanism.
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  • 74
    ISSN: 1432-0827
    Keywords: Hyperthyroidism ; Osteopenia ; Bisphosphonate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Hyperthyroidism, either endogenous or iatrogenic, leads to increased bone turnover and osteopenia. This study was conducted to examine (1) whether thyroid hormone excess in rats causes bone changes similar to those seen in patients with hyperthyroidism, and (2) the effects of the aminobisphosphonate alendronate on the thyroid hormone-induced bone changes. Sprague-Dawley male rats, divided into four groups, received L-thyroxine (T4) 250 μg/kg/day (+T4) or vehicle (-T4) subcutaneously six times per week and alendronate 1.75 mg/kg (+ALN) or vehicle (-ALN) orally twice a week. Rats were sacrificed after 3 weeks of treatment, blood samples were analyzed for serum T4, triiodo-L-thyronine (T3), and osteocalcin, and the proximal tibiae were processed for histomorphometric analysis. Serum T4 and T3 levels measured 20–24 hours after the last injection were 2 to 2.5-fold higher in +T4 groups than in-T4 groups. Serum osteocalcin was significantly (P 〈 0.05) higher in +T4/-ALN group than in the other groups, which were not statistically different from each other. T4 treatment (+T4/-ALN) significantly decreased the amount of cancellous bone volume (-45%) and increased osteoid surface (+254%), osteoblast surface (+111%), and osteoclast surface (+176%) relative to control values. Alendronate increased the bone volume above control values in both T4-treated (+ T4/ +ALN) and untreated (-T4/ +ALN) rats, and prevented the T4-induced increase in bone turnover in +T4/+ALN rats. It is concluded that (1) excess thyroid hormone induces cancellous bone loss associated with high bone turnover in the rat, and (2) this bone loss can be prevented by alendronate through the inhibition of osteoclastic activity.
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    Journal of molecular evolution 33 (1991), S. 442-449 
    ISSN: 1432-1432
    Keywords: Humans ; Mouse ; Rat ; Codon usage ; Mutation bias ; Selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A new statistical test has been developed to detect selection on silent sites. This test compares the codon usage within a gene and thus does not require knowledge of which genes are under the greatest selection, that there exist common trends in codon usage across genes, or that genes have the same mutation pattern. It also controls for mutational biases that might be introduced by the adjacent bases. The test was applied to 62 mammalian sequences, the significant codon usage biases were detected in all three species examined (humans, rats, and mice). However, these biases appear not to be the consequence of selection, but of the first base pair in the codon influencing the mutation pattern at the third position.
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    Journal of comparative physiology 170 (1992), S. 645-650 
    ISSN: 1432-1351
    Keywords: Milk ejection reflex ; Positive pressure oscillations ; Motor activity of pups ; Tactile stimulation of nipples ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes of positive pressure exerted by pups on nipples during sucking were investigated using anesthetized, lactating dams. It was found that, every 50–60 s, individual pups performed bouts of pressure oscillations (3/s) of high amplitude which lasted about 10–12 s and coincided with periods of increased motor activity. During the intervals, when pups were quiet, series of low-amplitude oscillations (3/s) were also observed. Using a strain measuring method to record the activity of sucking pups, synchronization of activity of two or more pups was found to occur periodically every 25–30 s and, most frequently, 10–30 s before the reflex increase of milk pressure. In further experiments, artificial tactile stimulation was applied to the dam's nipples using the joint action of suction and positive pressure. Following a short-term (10–20 s) increase in frequency and amplitude of artificial nipple stimulation, 60%–80% of all reflexive peaks of milk pressure were elicited with a latency of 19 ± 5 s. This suggests that there are specific conditions under which the stimulation of nipples by pups may trigger the formation of the milk ejection reflex in the rat.
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    Journal of comparative physiology 171 (1992), S. 657-664 
    ISSN: 1432-1351
    Keywords: Inferior olivary complex ; Cerebellum ; 3-acetylpyridine ; Harmaline ; Learning ; Memory ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary DA/HAN-strained male rats (pigmented rats) were submitted to two experimental tasks consisting of spatial learning (water-escape) and a passive avoidance conditioning. Both these tasks were performed by different animals. In order to destroy the inferior olivary complex, the animals were injected with 3-acetylpyridine either 9 days prior to the initial learning session or 24 h after completion of the learning task. They were retested (retrieval test) 10 days after the initial learning was achieved. Learning and retention were compared to those noted in control rats. Administration of 3-acetylpyridine before the initial learning did not prevent the spatial learning but the scores were greatly altered and the number of trials needed to reach the fixed learning criterion was much greater than in controls. However, 10 days later the animals had memorized their initial experience. Injection of 3-acetylpyridine after the initial learning session impaired memory: the animals had completely forgotten their initial learning. It can therefore be concluded that lesion of the afferent climbing fibres to the cerebellar cortex alters learning and retention of a spatial task. Such a lesion does not interfere with learning and retention of a passive avoidance conditioning, since in this condition the experimental animals injected with 3-acetylpyridine either before or after the initial learning behave similarly to controls. The effects of the inferior olivary complex lesion are obviously different according to the task to be learnt, suggesting that these two tasks do not require the integrity of the same nervous structures.
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    Journal of paleolimnology 10 (1994), S. 43-52 
    ISSN: 1573-0417
    Keywords: Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Charophyta are common algae in limnic waters from many regions and are an interesting group from an evolutionary point-of-view, as they are believed to be related to the Chlorophyceae and land plants. Paleontological-botanical systematics are discussed, taking into consideration some new advances. Charophytes live in all types of inland waters and are sensitive to ecological change, and so they are very useful paleolimnological markers. Gaps concerning gyrogonite morphology in extant taxa and their responses to different environmental conditions must be described. This paper discusses data concerning ecological factors affecting the distribution of Argentinian Charophyta (principally distributed between 30°S and 40°S), gyrogonite morphology related to different ecological conditions, and the way that Charophyta can modify the environment.
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    Journal of paleolimnology 10 (1994), S. 53-58 
    ISSN: 1573-0417
    Keywords: Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract The Pleistocene charophytes from Arroyo Perucho Verna, Province of Entre Ríos, were analyzed.Chara contraria Br. ex Kütz.,C. contraria var.longilinea Cáceres,C. globularis Thuill. andTolypella intricata (Trent. ex Roth.) Leonh. var.apiculata (A. Br.) Wood were described and illustrated with scanning electron microscope. The assemblage indicates fresh alkaline to slightly saline waters, not very deep, in a lentic or sometimes lotic environment. Extant assemblages provide data for this paleoecological reconstruction.
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  • 80
    ISSN: 1573-0832
    Keywords: Fusarium crookwellense ; temperature ; zearalenone ; a-zearalenol ; nivalenol ; mycotoxins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract After 6 weeks incubation on rice 2 strains of Fusarium crookwellense produced more zearalenone (6060–5010 mg/kg dry wt of culture) at ambient temperature (16–29°C) in daylight than at ambient temperature (18–23 °C) in darkness or at controlled temperatures of 11 °C, 20 °C or 25 °C in darkness. Yields at 25 °C were low. Incubation at 11 °C during the second 3 weeks incubation increased yields only when preliminary incubation had been at 25 °C. After 6 weeks incubation at controlled temperatures in darkness, 4 strains produced most zearalenone at 20 °C (2460-21 360 mg/kg), 1 strain at 11 °C (6570 mg/kg). Yields at a temperature oscillating daily from 10–20 °C were less than at 15 °C. One of the 5 strains produced appreciable amounts of a-zearalenol (1645 mg/kg at 20°C) and 2 of nivalenol (340 and 499 mg/kg at 20 °C).
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  • 81
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    Mycopathologia 123 (1993), S. 149-154 
    ISSN: 1573-0832
    Keywords: Ascending pyelonephritis ; Candida albicans ; Experimental model ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We developed a new experimental model of ascendingCandida pyelonephritis in female rats with leukopenia and vesicoureteral reflux. Rats were treated transperitoneally with cyclophosphamide (200 mg/kg) to induce leukopenia 3 days before and transurethrally with diluted acetic acid solution to induce vesicoureteral reflux 1 day before inoculation ofCandida albicans strain, ATCC 10259 (containing 107 cells). Microscopy revealed acute pyelonephritis in whichCandida cells invaded from the fornix and/or papilla into the medulla within 3 days after inoculation. Between 7 and 28 days after inoculation, chronic pyelonephritis reached the cortex. The incidence of pyelonephritis increased gradually and was approximately 80% after 7 days.Candida colony counts of bladder urine specimens obtained by direct puncture were significantly greater in rats with pyelonephritis extending into the parenchyma than in those with pyelonephritis located along the pelvis (p〈0.01). These results suggest that this rat model shows the characteristic feature of ascending pyelonephritis due toC. albicans and that the severity ofCandida pyelonephritis can be estimated fromCandida counts of bladder urine.
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  • 82
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    Nutrient cycling in agroecosystems 23 (1990), S. 97-103 
    ISSN: 1573-0867
    Keywords: Carbon ; mineralization ; nitrogen ; organic fertilizer ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The C and N mineralization characteristics of two organic N fertilizers were determined in a soil-less incubation system at three temperature regimes. Protox (derived from activated sewage sludge) initially degraded more rapidly by microbial action compared with dried blood. However, dried blood released more CO2-C and inorganic N towards the end of the incubation periods. The rate of microbial degradation increased with temperature. Mineralization characteristics of protein-based N sources are discussed in relation to organic N nutrition of vegetable crops.
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  • 83
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    Natural hazards 9 (1994), S. 5-16 
    ISSN: 1573-0840
    Keywords: Fourier transform ; maximum entropy spectral analysis ; precipitation ; temperature ; climatic change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract In the present work, a precipitation and temperature series from Barcelona (Spain) are analysed in order to detect the possible existence of climatic changes or cycles. The analysis is carried out both from the temporal and spectral standpoints. The techniques used range from the classical periodogram and Blackman-Tukey method through to the Maximum Entropy method. The results do not show the existence of climatic cycles, though they do show a clear tendency toward increased precipitation and decreased temperature, since the last years of series.
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  • 84
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    Antonie van Leeuwenhoek 61 (1992), S. 1-33 
    ISSN: 1572-9699
    Keywords: Paracoccus denitrificans ; denitrification ; methylotrophy ; cytochromec ; cytochrome oxidase ; phylogeny ; evolution ; lateral gene transfer ; nitrogen fixation ; Thiosphaera pantotropha
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Denitrification and methylotrophy inParacoccus denitrificans are discussed. The properties of the enzymes of denitrification: the nitrate-nitrite antiporter, nitrate reductase, nitrite reductase, nitric oxide reductase and nitrous oxide reductase are described. The genes for none of these proteins have yet been cloned and sequenced fromP. denitrificans. A number of sequences are available for enzymes fromEscherichia coli, Pseudomonas stutzeri andPseudomonas aeruginosa. It is concluded that pathway specificc-type cytochromes are involved in denitrification. At least 40 genes are involved in denitrification. In methanol oxidation at least 20 genes are involved. In this case too pathway specificc-type cytochromes are involved. The sequence homology between the quinoproteins methanol dehydrogenase, alcoholdehydrogenase and glucose dehydrogenase is discussed. This superfamily of proteins is believed to be derived from a common ancestor. ThemoxFJGI operon determines the structural components of methanol dehydrogenase and the associatedc-type cytochrome. Upstream of this operon 3 regulatory proteins were found. The mox Y protein shows the general features of a sensor protein and the moxX protein those of a regulatory protein. Thus a two component regulatory system is involved in both denitrification and methylotrophy. The phylogeny of prokaryotes based on 16S rRNA sequence is discussed. It is remarkable that the 16S rRNA ofThiosphaera pantotropha is identical to that ofP. denitrificans. Still these bacteria show a number of differences.T. pantotropha is able to denitrify under aerobic circumstances and it shows heterotrophic nitrification. Nitrification and heterotrophic nitrification are found in species belonging to the β-and γ-subdivisions of purple non-sulfur bacteria. Thus the occurrence of heterotrophic nitrification inT. pantotropha which belongs to the α-subdivision of purple non-sulfur bacteria is a remarkable property. FurthermoreT. pantotropha contains two nitrate reductases of which the periplasmic one is supposed to be involved in aerobic denitrification. The nitrite reductase is of the Cu-type and not of the cytochromecd 1 type as inP. denitrificans. Also the cytochromeb of theQbc complex ofT. pantotropha is highly similar to its counterpart inP. denitrificans. It is hypothesized that the differences between these two organisms which both contain large megaplasmids is due to a combination of loss of genetic information and plasmid-coded properties. The distribution of a number of complex metabolic systems in eubacteria and in a number of species belonging to the α-group of purple non sulphur bacteria is reviewed. Two possibilities to explain this haphazard distribution are considered: 1. Lateral gene transfer between distantly related micro organisms occurs frequently. 2. The eubacterial ancestors must have possessed already these properties. The distribution of these properties is due to sporadic loss during evolutionary divergence. With respect to the occurrence and frequency of lateral gene transfer two opposing views exist. According to molecular biologists lateral gene transfer occurs frequently and is very easy. Bacteria are supposed to form one large gene pool. On the other hand population geneticists have provided evidence that strong systems operate that establish reproductive isolation between diverged species and even between closely related cell lines. Data on amino acid sequences of nitrogenase proteins, cytochromesc, cytochrome oxidases, β-subunits of ATP synthase and tryptophan biosynthetic enzymes of various micro organisms were reviewed. In all these cases phylogenetic trees could be constructed based on the amino acid sequence data. In all cases this phylogenetic tree was similar to the one based on 16S rRNA homology. Only in one case evidence for the occurrence of lateral gene transfer was obtained. Therefore it is concluded that lateral gene transfer played a minor role in the distribution of complex metabolic systems among prokaryotes. It must be stressed that this does not exclude the possibility that lateral gene transfer occurred frequently in the initial stage of bacterial evolution. It is hypothesized that the appearance of nitrogen fixation, denitrification and cytochrome oxidase formation were early events in the evolution of micro organisms. Both systems are supposed to have evolved only once. Subsequently the capacity to fix nitrogen or to denitrifymust have been lost many times, just as photosynthetic capacity is supposed to have been lost many times. During evolution many systems have been lost leading to a haphazard distribution of metabolic characters among bacteria. As an example it is suggested that organisms with a respiratory chain similar to that ofEscherichia coli arose by loss of the capacity to form the Qbc complex andc-type cytochromes. The remaining systems could be controlled much better however than in the ancestral organisms.
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    Landscape ecology 6 (1991), S. 15-27 
    ISSN: 1572-9761
    Keywords: Climate ; microclimate ; energy balance ; dunes ; dune formation ; wind ; temperature ; precipitation ; evaporation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extremely important to the climate in any region are the radiation balance and the exchange processes of heat, water vapour and momentum. Most climatological parameters (e.g. temperature, humidity, wind speed, cloudiness and precipitation) are the direct or indirect result of the radiation balance and these exchange processes. The weather of the West European coast from Tarifa (Spain) to Skagen (Denmark) is especially suitable for the formation of dunes. Often a wind is blowing, varying widely in force and direction. The conditions are optimal for the formation of high and wide dune complexes, given a large supply of sand by the sea. The annual precipitation surplus is considerable for most of this coast. This favours the establishment of vegetation, and thereby it enhances dune formation. The short distance to the land-sea border causes strong gradients in several climatological parameters. These gradients lead to mesoscale effects, such as land-sea breezes and coastal fronts. The varying vegetation cover and the presence of slopes in all directions induce a strongly varying microclimate. However, this microclimate is not unique to the coastal dunes. Unique is the interaction with the wide range of ambient weather, which is inherent to the coast. It is not possible to be conclusive about the effects of climatic change on coastal dunes because climate models are not yet able to predict the changes adequately and because these models supply information on the expected mean climate, but not on the actual weather.
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    Biodegradation 5 (1994), S. 195-217 
    ISSN: 1572-9729
    Keywords: Aromatic catabolism ; by bacteria (Pseudomonas) ; evolution ; of catabolic pathways ; hydrocarbons ; catabolism of aromatic ; Pseudomonas ; evolution of catabolism in ; oxygenases ; evolution of
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The organisation and nucleotide sequences coding for the catabolism of benzene, toluene (and xylenes), naphthalene and biphenylvia catechol and the extradiol (meta) cleavage pathway inPseudomonas are reviewed and the various factors which may have played a part in their evolution are considered. The data suggests that the complete pathways have evolved in a modular way probably from at least three elements. The commonmeta pathway operons, downstream from the ferredoxin-like protein adjacent to the gene for catechol 2,3-dioxygenase, are highly homologous and clearly share a common ancestry. This common module may have become fused to a gene or genes the product(s) of which could convert a stable chemical (benzoate, salicylate, toluene, benzene, phenol) to catechol, thus forming the lower pathway operons found in modern strains. The upper pathway operons might then have been acquired as a third module at a later stage thus increasing the catabolic versatility of the host strains.
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    Journal of biomedical science 1 (1994), S. 201-203 
    ISSN: 1423-0127
    Keywords: Hypertension ; Eicosanoid ; Rat ; Genetics ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The present paper reviews the evidence for a possible involvement of renal eicosanoids in the pathophysiology of high blood pressure in genetically hypertensive rats of the Lyon strain. Both in vivo and in vitro experiments suggest that an increased ability to synthesize the vasoconstrictor prostaglandin H2 and/or thromboxane A2 in renal vessels (1) acts as an autocrine amplifier of pressor agents and (2) may contribute to resetting the pressure natriuresis curve which is a prerequisite for the development and maintenance of hypertension.
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  • 88
    ISSN: 1423-0445
    Keywords: toxin sequestration ; predation ; human dietary hazard ; cantharidin ; Coleoptera ; Meloidae ; Epicauta vittata ; Rana ; Hirudo ; Nerodia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Frogs(Rana pipiens) fed on blister beetles (Meloidae) or cantharidin, retain cantharidin systemically. After cessation of feeding, they void the compound relatively quickly. Systemic cantharidin does not protect frogs against ectoparasitic feeding by leeches(Hirudo medicinalis) or predation by snakes(Nerodia sipedon). As suggested by our data, and from reports in the early literature, ingestion of cantharidin-containing frogs can pose a health threat to humans.
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  • 89
    ISSN: 1423-0445
    Keywords: pheromone ; attractant ; triene ; tetraene ; hydrocarbon ; Insecta ; Coleoptera ; Nitidulidae ; Carpophilus freemani
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Males ofCarpophilus freemani Dobson (Coleoptera: Nitidulidae) produce an aggregation pheromone to which both sexes fly in a wind-tunnel bioassay. The major pheromone component (ca. 30 ng per male per day in volatile collections) was identified as (2E,4E,6E)-5-ethyl-3-methyl-2,4,6-nonatriene. A minor component, (2E,4E,6E,8E)-7-ethyl-3,5-dimethyl-2,4,6,8-undecatetraene, was 3–10% as abundant as the major triene and was 5–20% as active when compared at relative doses ranging from natural proportions to 1:1. These compounds act synergistically: a mixture of major and minor components in natural proportions attracted more than twice as many beetles as the major component alone, and the mixture fully accounted for the activity of male-derived volatile collections. Six other male-derived conjugated hydrocarbons, ranging from 2% down to 0.04% as abundant as the major component, were also identified. These are (in order of decreasing bioassay activity when compared on an equal-weight basis): (3E,5E,7E)-6-ethyl-4-methyl-3,5,7-decatriene, (2E,4E,6E)-5-ethyl-3-me-thyl-2,4,6-octatriene, (3E,5E,7E,9E)-8-ethyl-4,6-dimethyl-3, 5,7,9-dodecatetraene, (2E,4E,6E,8E)-3,5,7-trimethyl-2,4,6, 8-undecatetraene, (3E,5E,7E)-5-ethyl-7-methyl-3,5,7-undecatriene, and (2E,4E,6E)-3,5-dimethyl-2,4,6-nonatriene. All structure identifications were confirmed by synthesis. In the wind tunnel, the pheromone acted synergistically with “host”-type volatiles such as propyl acetate, valeric acid, and ethanol. This concept was verified by fields tests in California, in which there was dramatic synergism between the pheromone and fermenting host materials. Pheromone biosynthesis is discussed.
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  • 90
    ISSN: 1423-0445
    Keywords: secretion-grooming ; pygidial glands ; chemical defence against microorganisms ; respiration ; aquatic beetles ; Coleoptera ; Hydradephaga ; Gyrinidae ; Haliplidae ; Noteridae ; Hygrobiidae ; Dytiscidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary All Hydradephaga investigated so far crawl onto land when exposed to an increase in water temperature and light intensity and spread the secretion from their pygidial glands over the body surface (“secretion-grooming”). The secretions have antimicrobial properties and are mainly applied to hydrofuge body regions important for aquatic respiration. Experimental prevention of secretion-grooming leads to the loss of the respiratory air bubble and a significant increase in mortality. These findings support the view that the secretion-grooming of adephagous aquatic beetles, like in some aquatic Heteroptera, inhibits the growth of microor-ganisms, thus preventing the contamination and wetting of the cuticular respiratory structures. Thus it keeps functional the air-retaining hydrophobous body regions essential for aquatic respiration. A model is presented on how secretion-grooming may have evolved in the Hydradephaga. Other possible functions of the pygidial gland secretions are discussed.
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  • 91
    ISSN: 1423-0445
    Keywords: chemical defence ; mimicry ; reflex bleeding ; variation ; alkaloid ; coccinelline ; Coleoptera ; Coccinellidae ; Coccinella septempunctata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 7-spot ladybirds secrete alkaloid (coccinelline)-rich fluid (reflex blood) from leg joints as a defence mechanism against predators. A technique is described that enables the collection and accurate quantification of reflex blood produced, and the amount of coccinelline therein. Coccinelline was found distributed throughout the body, although concentrated in the reflex blood. Reflex blood was collected from a large set of beetles at several time points. Significant variation was found among beetles in the amount of reflex blood produced (for males and for females corrected for body weight) and the coccinelline concentration of the reflex blood. The results are discussed in relation to automimicry and the maintenance of variation through energy trade-offs. The relationships between tendency to aggregate, ability to reflex bleed and the possession of aposematic coloration are also considered.
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  • 92
    ISSN: 1423-0445
    Keywords: specificity ; predation ; long-range orientation ; windtunnel ; Coleoptera ; Rhizophagidae ; Scolytidae ; Rhizophagus grandis ; Dendroctonus micans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The predator,Rhizophagus grandis, is linked to its specific prey,Dendroctonus micans, by semiochemical signals regulating oviposition and long range orientation. A mixture of simple oxygenated monoterpenes [(−)—fenchone, (−)—pinocamphone, rac. camphor, terpinene-4-ol, borneol, fenchol and verbenone], identified from the frass ofD. micans has been found to be extremely active in a flight windtunnel as a long—range attractant for the predator. The mixture elicited 84 % of the response to larval frass of the prey. Excluding pinocamphone from the mixture did not influence its activity. Also, changing the absolute configurations of some of the components (fenchol, terpinene-4-ol and borneol) did not influence the predators' response. However, the addition of (−)—α-terpineol increased the attractivity of the synthetic blend to almost that of larval frass of the prey. Ecological implications of the identified semiochemicals and their use in pest management are discussed.
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  • 93
    ISSN: 1423-0445
    Keywords: sequestration ; pharmacophagy ; defense ; allomone ; kairomone ; cucurbitacin ; Cucurbitaceae ; Coleoptera ; Chrysomelidae ; Luperini ; Diabrotica ; Aulacophora
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.
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  • 94
    ISSN: 1423-0445
    Keywords: chemical defence ; tri-trophic interactions ; alkaloids ; Homoptera ; Aphis craccivora ; Icerya spp. ; Lepidosaphes ulmi ; Planococcus citri ; Coleoptera ; Coccinellidae ; Cryptolaemus montrouzieri ; Rodolia cardinalis ; Chilocorus bipustulatus ; Neuroptera ; Chrysopidae ; Chrysoperla carnea ; Hymenoptera ; Encyrtidae ; Encyrtus infelix ; Leguminosae ; Erythrina corallodendrum ; Spartium junceum ; Citrus sinensis ; Euphorbia tirucalli ; Pittosporum tobira
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.
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    Chemoecology 4 (1993), S. 29-32 
    ISSN: 1423-0445
    Keywords: chemical defence ; alkaloids ; predation ; Coleoptera ; Coccinellidae ; Adalia bipunctata ; Coccinella septempunctata ; Hymenoptera ; Formicidae ; Lasius niger
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Garden black ants,Lasius niger L., in a laboratory colony, attacked three species of live ladybirds found near their nest, killing the smaller two species. A second colony was offered artificial diets containing crushed ladybirds of two species, and the ants' choice of feeding site noted. Both the diets were aversive compared to control, but that containing 7spot,Coccinella septempunctata L., was more aversive than the diet containing 2spot,Adalia bipunctata L. The implications of this lesser protection for 2spots in terms of the chemical defence of the species are discussed.
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    Development genes and evolution 204 (1994), S. 62-69 
    ISSN: 1432-041X
    Keywords: Cell determination ; direct development dorsoventral axis ; echinoids ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the direct-developing sea urchinHeliocidaris erythrogramma the first cleavage division bisects the dorsoventral axis of the developing embryo along a frontal plane. In the two-celled embryo one of the blastomeres, the ventral cell (V), gives rise to all pigmented mesenchyme, as well as to the vestibule of the echinus rudiment. Upon isolation, however, the dorsal blastomere (D) displays some regulation, and is able to form a small number of pigmented mesenchyme cells and even a vestibule. We have examined the spatial and temporal determination of cell fates along the dorsoventral axis during subsequent development. We demonstrate that the dorsoventral axis is resident within both cells of the two-celled embryo, but only the ventral pole of this axis has a rigidly fixed identity this early in development. The polarity of this axis remains the same in half-embryos developing from isolated ventral (V) blastomeres, but it can flip 180° in half-embryos developing from isolated dorsal (D) blastomeres. We find that cell fates are progressively determined along the dorsoventral axis up to the time of gastrulation. The ability of dorsal half-embryos to differentiate ventral cell fates diminishes as they are isolated at progressively later stages of development. These results suggest that the determination of cell fates along the dorsoventral axis inH. erythrogramma is regulated via inductive interactions organized by cells within the ventral half of the embryo.
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    Pure and applied geophysics 141 (1993), S. 487-495 
    ISSN: 1420-9136
    Keywords: Pressure ; temperature ; hydrothermal ; H2O ; equation of state ; diamond anvil cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The new hydrothermal diamond anvil cell (HDAC) has been designed for optical microscopy and X-ray diffraction at pressures up to 10 GPa and temperatures between −190°C and 1200°C. Laser light reffected from the top and bottom anvil faces and the top and bottom solid sample faces produce interference fringes that provide a very sensitive means of monitoring the volume of sample chamber and for observing volume and refractive index changes in solid samples due to transitions and reactions. Synchrotron radiation has been used to make X-ray diffraction patterns of samples under hydrothermal conditions. Individual heaters and individual thermocouples provide temperature control with an accuracy of ±0.5°C. Liquid nitrogen directly introduced into the HDAC has been used to reduce the sample temperature to −190°C. The α-β phase boundary of quartz has been used to calculate the transition pressures from measured transition temperatures. With this method we have redetermined 5 isochores of H2O up to 850°C and 1.2 GPa at which the solution rate of the quartz became so rapid that the quartz dissolved completely before the α-β transition could be observed. When silica solutions were cooled, opal spherules and rods formed.
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  • 98
    ISSN: 1420-9136
    Keywords: Pressure ; temperature ; stress ; measurement ; acoustic emissions ; deformation ; techniques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract New and improved techniques and apparatus for testing the mechanical properties of materials at high presures and temperatures are described. These include an improved Griggs-type deformation apparatus designed to operate to 5 GPa and associated servo-controlled hydraulic drive and electronics, the design of hydrostatic (molten alkali halide mixtures) pressure assemblies to measure flow stresses as low as a few MPa, the characterization of temperature gradients and friction in such assemblies, measurement of the melting curve of an alkali halide mixture used as a confining pressure medium, and the measurement of acoustic emissions.
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  • 99
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    Insectes sociaux 38 (1991), S. 263-272 
    ISSN: 1420-9098
    Keywords: Isoptera ; Kalotermitidae ; Neotermes papua ; termites ; caste differentiation ; division of labour ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The direct development ofNeotermes papua (Isoptera: Kalotermitidae) comprises four larval and three nymphal instars before the alate. The first five instars can be easily characterized. The second stage nymphs come morphologically close to the pseudergates, characterized by reduced wing buds. These nymphs can moult stationarily, i.e. with little morphological change, or to presoldiers, or proceed to the alate via the third nymphal stage. Pseudergates originate through a late and reversible deviation from the straight development to the alate. Presoldiers may derive from several stages, up to the last nymphal one; their production is subject to an inhibition by extant soldiers. This developmental schema is congruent with those described in other Kalotermitidae and the Termopsidae. By pinpointing the existence of a large pool of pluripotent individuals, in which the penultimate nymphal stage mingles with pseudergates, the present study also reveals a great similarity betweenNeotermes andProrhinotermes, and suggests that this developmental schema might be generally applicable to termites devoid of a permanent worker caste.
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 40 (1993), S. 325-335 
    ISSN: 1420-9098
    Keywords: Formicidae ; social parasitism ; PCR ; 18 S ribosomal RNA ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The evolutionary relationship between socially parasitic ants and their hosts is still an unsolved problem. We have compared a 1.2 kb sequence of the 18 S ribosomal RNA genes of the parasitic antsDoronomyrmex kutteri, Harpagoxenus sublaevis andChalepoxenus muellerianus to the sequence of the host speciesLeptothorax acervorum andL. recedens (all subfamily Myrmicinae, tribe Leptothoracini) and to an out-group antCamponotus ligniperda (Formicinae). We found that parasitic species and the host species and alsoCamponotus ligniperda differ at less than 1% of the base positions of the 1.2 kb segment of the 18S rRNA gene. The sequences showed 80.3% identity to the 18 S ribosomal RNA genes of the beetleTenebrio molitor and only 66.5% to that of the dipteranDrosophila melanogaster.
    Type of Medium: Electronic Resource
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